Re: [postgis-users] Basic postgis raster questions
postgis-users-boun...@postgis.refractions.net wrote on 06/15/2011 07:49:15 PM: > I totally agree but a wrapper would be convenient for people not > familiar with intersection operations on raster. Most are familiar > with vector/vector intersections on but not with raster/raster ones. I'm not against wrappers, particularly if the documentation makes it clear what the wrapper is wrapping. Wrappers+documentation can be used as a learning tool to show how the raster/raster operations are really the same thing as the corresponding vector/vector operation. BTW: I posted this to the devel list, but anyone on the users list interested is also welcome to review and criticize my "philosophy" on homogeneous vector/raster operations. This is mostly for my own benefit to try and wrap my head around the big picture by teasing out the fundamental issues. https://collab.firelab.org/software/projects/modisfire/wiki/Spatial_Set_Operations_in_PostGIS_Raster Bryce___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction
James, There a couple of SQL plugins for QGIS. They allow you to visualize spatial features via 'ad hoc' queries (not whole tables). I am pretty sure that I used the RT_SQL plugin. Here is a link to some info: http://underdark.wordpress.com/2010/10/16/visualizing-postgis-queries-in-qgis-using-rt-sql-layer-plugin/ No need to buy a $10,000 proprietary desktop GIS... David. On Wed, Jun 15, 2011 at 1:33 PM, James David Smith wrote: > Dear Cristian & David, > > Thanks alot for your responses. > > Cristian - I don't have money to buy additional software > unfortunately. With regard to 'view' I actually don't know what this > is. I'm a bit of a beginner. I wonder if I made a 'view' whether I > could then query that view with QGIS. Something for me to look into... > > David - That looks like a good idea... but when adding data to QGIS > you can only select the whole table (I think) and then you manually > enter the 'WHERE' clause in a dialog box. I guess I could run the > query you suggest in PostgreSQL and save it into another table... and > then link QGIS to the new table. Though it all starts to get a bit > convoluted if I have to do that every time I want to look at some data > in QGIS... > > Cheers > > James > > > > On 15 June 2011 19:16, David Fawcett wrote: >> This is what is really cool about using a database to store your data... >> >> Change your query to: >> >> SELECT mycol1, >> mycol2, >> date_time_of_arrival as dt_arrive, >> date_time_of_departure as dt_depart, >> the_geom >> FROM incidents >> WHERE urgency = 'Immediate' >> AND date_time_of_arrival - date_time_unit_assigned > '00:12:00' >> >> Note: you will need to specify the names of the columns that you are >> interested in. >> >> >> On Wed, Jun 15, 2011 at 12:58 PM, James David Smith >> wrote: >>> Dear all, >>> >>> I appreciate that this is more of a QGIS query, but I think that the >>> route of the problem might be in PostGIS, so... I have opened QGIS and >>> ran the query on my PostGIS table as below: >>> >>> SELECT * FROM incidents >>> WHERE urgency = 'Immediate' >>> AND date_time_of_arrival - date_time_unit_assigned > '00:12:00' >>> >>> This gives me 33 points in QGIS. Great. I would now however like to >>> save this as a ShapeFile for use in ArcGIS with which I am more >>> familiar, but when I try to SAVE AS from QGIS I am given the following >>> error >>> >>> Export to vector file failed. >>> Error: trimming attribute name 'date_time_of_arrival' to ten >>> significant characters produces duplicate column name. >>> >>> I am guessing that the problem here is that ESRI shapefiles can only >>> deal with column names that are ten characters long...? And that as I >>> also have a column called 'date_time_of_departure', when QGIS trims >>> this column it ends up with two columns called the same thing? Is >>> there a way around this? I realise I could rename the column in QGIS, >>> but I actually have around 45 columns in the table and this problem >>> will occur with about 15 pairs of them I think. I guess there is no >>> simple answer... but thought I'd ask. >>> >>> Cheers >>> >>> James >>> ___ >>> postgis-users mailing list >>> postgis-users@postgis.refractions.net >>> http://postgis.refractions.net/mailman/listinfo/postgis-users >>> >> ___ >> postgis-users mailing list >> postgis-users@postgis.refractions.net >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> > ___ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users > ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Basic postgis raster questions
An of course: ST_Union()... But if we get an efficient ST_MapAlgebra(raster, raster) I'll do it for you in one day :-) > -Original Message- > From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users- > boun...@postgis.refractions.net] On Behalf Of Pierre Racine > Sent: Wednesday, June 15, 2011 3:49 PM > To: PostGIS Users Discussion > Subject: Re: [postgis-users] Basic postgis raster questions > > I totally agree but a wrapper would be convenient for people not familiar with > intersection operations on raster. Most are familiar with vector/vector > intersections on but not with raster/raster ones. So let's inverse 4) and 5) > in my > previous mail. > > I think the only real major missing pieces are: > > 1) ST_AsRaster(geometry) > > 2) ST_Resample(raster) > > 3) ST_MapAlgebra(raster, raster) > > And then the things we can not do with them. > > Pierre > > > -Original Message- > > From: postgis-users-boun...@postgis.refractions.net > > [mailto:postgis-users- boun...@postgis.refractions.net] On Behalf Of > > Bryce L Nordgren > > Sent: Wednesday, June 15, 2011 3:38 PM > > To: PostGIS Users Discussion > > Subject: Re: [postgis-users] Basic postgis raster questions > > > > > > > > postgis-users-boun...@postgis.refractions.net wrote on 06/15/2011 > > 07:02:46 > > PM: > > > > > > 4. ST_Clip(raster, geometry) > > > > If ST_Intersection(raster, geometry) returns a raster having the > > original pixel values inside the geometry, and nodata outside the > > geometry, I'm not sure I see the need for a separate "clip" function. > Semantically and mathematically, "clip" > > is "intersection": area common to both arguments. > > > > Bryce > ___ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction
Regina, I'm doing this against my production PostGIS 1.5 server. -bborie On 06/15/2011 12:18 PM, Paragon Corporation wrote: Bborie, Does this work for any version of PostGIS or only ESRI sanctioned PostGIS 1.4? Thanks, Regina http://www.postgis.us -Original Message- From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of Bborie Park Sent: Wednesday, June 15, 2011 3:10 PM To: doug_newc...@fws.gov Cc: postgis-users@postgis.refractions.net Subject: Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction Hey Doug, ArcMap 10 brought "read-only" access to PostGIS without the need for ArcSDE or any other extensions. To do so... 1. Click on File> Add Data> Add Query Layer... 2. In the "New Query Layer" window that appears, click on the "Connections..." button to add a new connection. Unless you have existing connnections, click on "New..." in the "Manage Connection(s)" window. 3. In the "Database Connection" window, select "postgresql" for the DBMS client, provide your database server IP (or domain name) in "Data Source" and fill out "Database" with the name of the database you're connecting to. If need be, add the appropriate authentication information. For PostgreSQL, you'll select "Database Authentication" for Authentication. Feel free to test your settings with "Test Connection". 4. Once satisfied, click "OK" to close the "Database Connection" window. 5. By now, you should have an entry in the "Manage Connection(s)" window so click "OK" if you're satisfied. 6. You should be back in "New Query Layer" and the connection you just created may have already been selected for "Connection". If not, select the appropriate connection. It takes a few seconds for the connection to be established and the program to retrieve the schema of the database. 7. I usually skip clicking on the "List of Tables" and "Columns" tools as ArcGIS still doesn't work with 64-bit datatypes (double, bigint, text???) and go directly to the "Name" and "Query" elements on the window. Just provide a value for "Name" as that value will be the layer name and use any valid SQL SELECT statement in the "Query" field. 8. You can click on "Validate" to make sure your query is valid. Once, satisfied, click on "Finish" That's it. -bborie On 06/15/2011 11:53 AM, doug_newc...@fws.gov wrote: bborie, I would like details on this procedure. Does it require the interoperability extension? Ziggis? Doug Doug Newcomb USFWS Raleigh, NC 919-856-4520 ext. 14 doug_newc...@fws.gov -- --- The opinions I express are my own and are not representative of the official policy of the U.S.Fish and Wildlife Service or Dept. of the Interior. Life is too short for undocumented, proprietary data formats. -postgis-users-boun...@postgis.refractions.net wrote: - To: postgis-users@postgis.refractions.net From: Bborie Park Sent by: postgis-users-boun...@postgis.refractions.net Date: 06/15/2011 06:47PM Subject: Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction James, If you have ArcGIS 10, you can directly write SELECT queries from ArcMap to PostGIS. That's how I visualize my data when I'm running Windows. -bborie On 06/15/2011 10:58 AM, James David Smith wrote: Dear all, I appreciate that this is more of a QGIS query, but I think that the route of the problem might be in PostGIS, so... I have opened QGIS and ran the query on my PostGIS table as below: SELECT * FROM incidents WHERE urgency = 'Immediate' AND date_time_of_arrival - date_time_unit_assigned> '00:12:00' This gives me 33 points in QGIS. Great. I would now however like to save this as a ShapeFile for use in ArcGIS with which I am more familiar, but when I try to SAVE AS from QGIS I am given the following error Export to vector file failed. Error: trimming attribute name 'date_time_of_arrival' to ten significant characters produces duplicate column name. I am guessing that the problem here is that ESRI shapefiles can only deal with column names that are ten characters long...? And that as I also have a column called 'date_time_of_departure', when QGIS trims this column it ends up with two columns called the same thing? Is there a way around this? I realise I could rename the column in QGIS, but I actually have around 45 columns in the table and this problem will occur with about 15 pairs of them I think. I guess there is no simple answer... but thought I'd ask. Cheers James ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users -- Bborie Park Programmer Center for Vectorborne Diseases UC Davis 530-752-8380 bkp...@ucdavis.edu ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refraction
Re: [postgis-users] Basic postgis raster questions
I totally agree but a wrapper would be convenient for people not familiar with intersection operations on raster. Most are familiar with vector/vector intersections on but not with raster/raster ones. So let's inverse 4) and 5) in my previous mail. I think the only real major missing pieces are: 1) ST_AsRaster(geometry) 2) ST_Resample(raster) 3) ST_MapAlgebra(raster, raster) And then the things we can not do with them. Pierre > -Original Message- > From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users- > boun...@postgis.refractions.net] On Behalf Of Bryce L Nordgren > Sent: Wednesday, June 15, 2011 3:38 PM > To: PostGIS Users Discussion > Subject: Re: [postgis-users] Basic postgis raster questions > > > > postgis-users-boun...@postgis.refractions.net wrote on 06/15/2011 07:02:46 > PM: > > > > 4. ST_Clip(raster, geometry) > > If ST_Intersection(raster, geometry) returns a raster having the original > pixel > values inside the geometry, and nodata outside the geometry, I'm not sure I > see > the need for a separate "clip" function. Semantically and mathematically, > "clip" > is "intersection": area common to both arguments. > > Bryce ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Basic postgis raster questions
postgis-users-boun...@postgis.refractions.net wrote on 06/15/2011 07:02:46 PM: > > 4. ST_Clip(raster, geometry) If ST_Intersection(raster, geometry) returns a raster having the original pixel values inside the geometry, and nodata outside the geometry, I'm not sure I see the need for a separate "clip" function. Semantically and mathematically, "clip" is "intersection": area common to both arguments. Bryce___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction
Bborie, Does this work for any version of PostGIS or only ESRI sanctioned PostGIS 1.4? Thanks, Regina http://www.postgis.us -Original Message- From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of Bborie Park Sent: Wednesday, June 15, 2011 3:10 PM To: doug_newc...@fws.gov Cc: postgis-users@postgis.refractions.net Subject: Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction Hey Doug, ArcMap 10 brought "read-only" access to PostGIS without the need for ArcSDE or any other extensions. To do so... 1. Click on File > Add Data > Add Query Layer... 2. In the "New Query Layer" window that appears, click on the "Connections..." button to add a new connection. Unless you have existing connnections, click on "New..." in the "Manage Connection(s)" window. 3. In the "Database Connection" window, select "postgresql" for the DBMS client, provide your database server IP (or domain name) in "Data Source" and fill out "Database" with the name of the database you're connecting to. If need be, add the appropriate authentication information. For PostgreSQL, you'll select "Database Authentication" for Authentication. Feel free to test your settings with "Test Connection". 4. Once satisfied, click "OK" to close the "Database Connection" window. 5. By now, you should have an entry in the "Manage Connection(s)" window so click "OK" if you're satisfied. 6. You should be back in "New Query Layer" and the connection you just created may have already been selected for "Connection". If not, select the appropriate connection. It takes a few seconds for the connection to be established and the program to retrieve the schema of the database. 7. I usually skip clicking on the "List of Tables" and "Columns" tools as ArcGIS still doesn't work with 64-bit datatypes (double, bigint, text???) and go directly to the "Name" and "Query" elements on the window. Just provide a value for "Name" as that value will be the layer name and use any valid SQL SELECT statement in the "Query" field. 8. You can click on "Validate" to make sure your query is valid. Once, satisfied, click on "Finish" That's it. -bborie On 06/15/2011 11:53 AM, doug_newc...@fws.gov wrote: > > bborie, > I would like details on this procedure. Does it require the > interoperability extension? Ziggis? > > Doug > > Doug Newcomb > USFWS > Raleigh, NC > 919-856-4520 ext. 14 doug_newc...@fws.gov > -- > --- > > The opinions I express are my own and are not representative of the > official policy of the U.S.Fish and Wildlife Service or Dept. of the > Interior. Life is too short for undocumented, proprietary data formats. > > -postgis-users-boun...@postgis.refractions.net wrote: - > > To: postgis-users@postgis.refractions.net > From: Bborie Park > Sent by: postgis-users-boun...@postgis.refractions.net > Date: 06/15/2011 06:47PM > Subject: Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction > > James, > > If you have ArcGIS 10, you can directly write SELECT queries from > ArcMap to PostGIS. That's how I visualize my data when I'm running Windows. > > -bborie > > On 06/15/2011 10:58 AM, James David Smith wrote: >> Dear all, >> >> I appreciate that this is more of a QGIS query, but I think that the >> route of the problem might be in PostGIS, so... I have opened QGIS >> and ran the query on my PostGIS table as below: >> >> SELECT * FROM incidents >> WHERE urgency = 'Immediate' >> AND date_time_of_arrival - date_time_unit_assigned>'00:12:00' >> >> This gives me 33 points in QGIS. Great. I would now however like to >> save this as a ShapeFile for use in ArcGIS with which I am more >> familiar, but when I try to SAVE AS from QGIS I am given the >> following error >> >> Export to vector file failed. >> Error: trimming attribute name 'date_time_of_arrival' to ten >> significant characters produces duplicate column name. >> >> I am guessing that the problem here is that ESRI shapefiles can only >> deal with column names that are ten characters long...? And that as I >> also have a column called 'date_time_of_departure', when QGIS trims >> this column it ends up with two columns called the same thing? Is >> there a way around this? I realise I could rename the column in QGIS, >> but I actually have around 45 columns in the table and this problem >> will occur with about 15 pairs of them I think. I guess there is no >> simple answer... but thought I'd ask. >> >> Cheers >> >> James >> ___ >> postgis-users mailing list >> postgis-users@postgis.refractions.net >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> > > -- > Bborie Park > Programmer > Center for Vectorborne Diseases > UC Davis > 530-752-8380 > bkp...@ucdavis.edu > ___ > postgis-users mailing list >
Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction
Hey Doug, ArcMap 10 brought "read-only" access to PostGIS without the need for ArcSDE or any other extensions. To do so... 1. Click on File > Add Data > Add Query Layer... 2. In the "New Query Layer" window that appears, click on the "Connections..." button to add a new connection. Unless you have existing connnections, click on "New..." in the "Manage Connection(s)" window. 3. In the "Database Connection" window, select "postgresql" for the DBMS client, provide your database server IP (or domain name) in "Data Source" and fill out "Database" with the name of the database you're connecting to. If need be, add the appropriate authentication information. For PostgreSQL, you'll select "Database Authentication" for Authentication. Feel free to test your settings with "Test Connection". 4. Once satisfied, click "OK" to close the "Database Connection" window. 5. By now, you should have an entry in the "Manage Connection(s)" window so click "OK" if you're satisfied. 6. You should be back in "New Query Layer" and the connection you just created may have already been selected for "Connection". If not, select the appropriate connection. It takes a few seconds for the connection to be established and the program to retrieve the schema of the database. 7. I usually skip clicking on the "List of Tables" and "Columns" tools as ArcGIS still doesn't work with 64-bit datatypes (double, bigint, text???) and go directly to the "Name" and "Query" elements on the window. Just provide a value for "Name" as that value will be the layer name and use any valid SQL SELECT statement in the "Query" field. 8. You can click on "Validate" to make sure your query is valid. Once, satisfied, click on "Finish" That's it. -bborie On 06/15/2011 11:53 AM, doug_newc...@fws.gov wrote: bborie, I would like details on this procedure. Does it require the interoperability extension? Ziggis? Doug Doug Newcomb USFWS Raleigh, NC 919-856-4520 ext. 14 doug_newc...@fws.gov - The opinions I express are my own and are not representative of the official policy of the U.S.Fish and Wildlife Service or Dept. of the Interior. Life is too short for undocumented, proprietary data formats. -postgis-users-boun...@postgis.refractions.net wrote: - To: postgis-users@postgis.refractions.net From: Bborie Park Sent by: postgis-users-boun...@postgis.refractions.net Date: 06/15/2011 06:47PM Subject: Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction James, If you have ArcGIS 10, you can directly write SELECT queries from ArcMap to PostGIS. That's how I visualize my data when I'm running Windows. -bborie On 06/15/2011 10:58 AM, James David Smith wrote: Dear all, I appreciate that this is more of a QGIS query, but I think that the route of the problem might be in PostGIS, so... I have opened QGIS and ran the query on my PostGIS table as below: SELECT * FROM incidents WHERE urgency = 'Immediate' AND date_time_of_arrival - date_time_unit_assigned>'00:12:00' This gives me 33 points in QGIS. Great. I would now however like to save this as a ShapeFile for use in ArcGIS with which I am more familiar, but when I try to SAVE AS from QGIS I am given the following error Export to vector file failed. Error: trimming attribute name 'date_time_of_arrival' to ten significant characters produces duplicate column name. I am guessing that the problem here is that ESRI shapefiles can only deal with column names that are ten characters long...? And that as I also have a column called 'date_time_of_departure', when QGIS trims this column it ends up with two columns called the same thing? Is there a way around this? I realise I could rename the column in QGIS, but I actually have around 45 columns in the table and this problem will occur with about 15 pairs of them I think. I guess there is no simple answer... but thought I'd ask. Cheers James ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users -- Bborie Park Programmer Center for Vectorborne Diseases UC Davis 530-752-8380 bkp...@ucdavis.edu ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users -- Bborie Park Programmer Center for Vectorborne Diseases UC Davis 530-752-8380 bkp...@ucdavis.edu ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Basic postgis raster questions
> Pierre, > > Is it safe to assume that what you're looking for is a ST_AsRaster to convert > the > geometry into a raster so that we can do raster on raster filtering? This is VERY userful but not sufficient. > I've been wondering as to which method (covert raster to vector or convert > vector to raster) is more efficient, hence my delay in adding a geometry > parameter to filter a raster. I haven't done any test yet but I am pretty sure that geometry to raster is much faster. You could easily test test "gdal_rasterize" VS "gdal_polygonize.py" even though one is in Python and the other one seems to be in C. > Then again, I've been thinking that there are fundamental functions that > should > be implemented first, including: > > 1. ST_AsRaster(geometry) > > 2. ST_Resample(raster) > > 3. ST_Intersection(raster, raster) > > 4. ST_Clip(raster, geometry) I think 3) is more or less optional as it could easily be implemented as a wrapper around the two rasters version of MapAlgebra. I agree that ST_AsRaster(geometry) and ST_Resample(raster) are all very fundamental missing pieces. ST_Clip could be implemented using ST_AsRaster(geometry) and ST_MapAlgebra(raster, raster) because ST_Mapalgebra have a 'working extent' parameter. If you set it to 'INTERSECTION of both raster' and the computing expression is 'rast2' then ST_MapAlgebra(ST_AsRaster(geometry), raster) is ST_Clip(raster, geometry) So in my head: 1) ST_AsRaster(geometry) 2) ST_Resample(raster) 3) ST_MapAlgebra(raster, raster) 4) ST_Clip 5) St_Intersection(raster, raster) With that we can certainly implement stats restricted to geometry: ST_SummaryStat(ST_Intersection(raster, ST_AsRaster(geometry))) But how fast would it be? But we can implement thousands of other things with those functions... mostly with ST_Mapalgebra(raster, raster). Pierre ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction
James, If you have ArcGIS 10, you can directly write SELECT queries from ArcMap to PostGIS. That's how I visualize my data when I'm running Windows. -bborie On 06/15/2011 10:58 AM, James David Smith wrote: Dear all, I appreciate that this is more of a QGIS query, but I think that the route of the problem might be in PostGIS, so... I have opened QGIS and ran the query on my PostGIS table as below: SELECT * FROM incidents WHERE urgency = 'Immediate' AND date_time_of_arrival - date_time_unit_assigned> '00:12:00' This gives me 33 points in QGIS. Great. I would now however like to save this as a ShapeFile for use in ArcGIS with which I am more familiar, but when I try to SAVE AS from QGIS I am given the following error Export to vector file failed. Error: trimming attribute name 'date_time_of_arrival' to ten significant characters produces duplicate column name. I am guessing that the problem here is that ESRI shapefiles can only deal with column names that are ten characters long...? And that as I also have a column called 'date_time_of_departure', when QGIS trims this column it ends up with two columns called the same thing? Is there a way around this? I realise I could rename the column in QGIS, but I actually have around 45 columns in the table and this problem will occur with about 15 pairs of them I think. I guess there is no simple answer... but thought I'd ask. Cheers James ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users -- Bborie Park Programmer Center for Vectorborne Diseases UC Davis 530-752-8380 bkp...@ucdavis.edu ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Basic postgis raster questions
On 06/15/2011 07:03 AM, Pierre Racine wrote: I may be missing the boat here, but it seems to me that a version of ST_Intersection() which returns a raster would eliminate the need for a separate geometry parameter, and would be more in line with the spirit of "seamless vector/raster" processing. It also would seem that your separate geometry parameter would behave very much like a raster-returning ST_Intersection(), except that it is only usable "vicariously" via the stats functions. Right. It would even be of greater value for other functionalities even if, I think, it would be slower for the particular case of computing stats . Sorry but I must come back on this. This is true when the vector area is small in comparison with the raster area AND if the raster coverage is tiled. In this case vectorization is possible and provide results very fast. This is true also if the raster is not tiled but is small. This operation provide very precise numbers because the intersection is done in vector mode and every pixel are cut when necessary. What you get is not a mere count of the pixels intersecting "a la Starspan" but true areas. In the other case (if the vector area is big in comparison the raster area OR the raster is big and not tiled) the all vector method is catastrophic as you have to vectorize many time large parts of the raster and this become unpracticable. This is why we need a pixel counter (ST_Histogram) accepting geometries. The provided result are somewhat coarser (take all the pixel or nothing) and provide a "a la Starspan" result, but at last, provide a result in reasonable time. This is why we need ST_Histogram, ST_SummaryStat, etc., accepting a geometry as parameter. Pierre, Is it safe to assume that what you're looking for is a ST_AsRaster to convert the geometry into a raster so that we can do raster on raster filtering? I've been wondering as to which method (covert raster to vector or convert vector to raster) is more efficient, hence my delay in adding a geometry parameter to filter a raster. Then again, I've been thinking that there are fundamental functions that should be implemented first, including: 1. ST_AsRaster(geometry) 2. ST_Resample(raster) 3. ST_Intersection(raster, raster) 4. ST_Clip(raster, geometry) -bborie -- Bborie Park Programmer Center for Vectorborne Diseases UC Davis 530-752-8380 bkp...@ucdavis.edu ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction
James, You can use shp2pgsql command line packaged with PostGIS. It automatically renames columns for you by adding digits to the end of duplicated 10char names So something like pgsql2shp -f myshapefile -h myserver -u apguser -P apgpassword mygisdb "SELECT * FROM incidents WHERE urgency = 'Immediate' AND date_time_of_arrival - date_time_unit_assigned > '00:12:00' " http://www.bostongis.com/pgsql2shp_shp2pgsql_quickguide_20.bqg Leo http://www.postgis.us -Original Message- From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of James David Smith Sent: Wednesday, June 15, 2011 1:58 PM To: PostGIS Users Discussion Subject: [postgis-users] QGIS - PostGIS - ArcGIS Interaction Dear all, I appreciate that this is more of a QGIS query, but I think that the route of the problem might be in PostGIS, so... I have opened QGIS and ran the query on my PostGIS table as below: SELECT * FROM incidents WHERE urgency = 'Immediate' AND date_time_of_arrival - date_time_unit_assigned > '00:12:00' This gives me 33 points in QGIS. Great. I would now however like to save this as a ShapeFile for use in ArcGIS with which I am more familiar, but when I try to SAVE AS from QGIS I am given the following error Export to vector file failed. Error: trimming attribute name 'date_time_of_arrival' to ten significant characters produces duplicate column name. I am guessing that the problem here is that ESRI shapefiles can only deal with column names that are ten characters long...? And that as I also have a column called 'date_time_of_departure', when QGIS trims this column it ends up with two columns called the same thing? Is there a way around this? I realise I could rename the column in QGIS, but I actually have around 45 columns in the table and this problem will occur with about 15 pairs of them I think. I guess there is no simple answer... but thought I'd ask. Cheers James ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction
Dear Cristian & David, Thanks alot for your responses. Cristian - I don't have money to buy additional software unfortunately. With regard to 'view' I actually don't know what this is. I'm a bit of a beginner. I wonder if I made a 'view' whether I could then query that view with QGIS. Something for me to look into... David - That looks like a good idea... but when adding data to QGIS you can only select the whole table (I think) and then you manually enter the 'WHERE' clause in a dialog box. I guess I could run the query you suggest in PostgreSQL and save it into another table... and then link QGIS to the new table. Though it all starts to get a bit convoluted if I have to do that every time I want to look at some data in QGIS... Cheers James On 15 June 2011 19:16, David Fawcett wrote: > This is what is really cool about using a database to store your data... > > Change your query to: > > SELECT mycol1, > mycol2, > date_time_of_arrival as dt_arrive, > date_time_of_departure as dt_depart, > the_geom > FROM incidents > WHERE urgency = 'Immediate' > AND date_time_of_arrival - date_time_unit_assigned > '00:12:00' > > Note: you will need to specify the names of the columns that you are > interested in. > > > On Wed, Jun 15, 2011 at 12:58 PM, James David Smith > wrote: >> Dear all, >> >> I appreciate that this is more of a QGIS query, but I think that the >> route of the problem might be in PostGIS, so... I have opened QGIS and >> ran the query on my PostGIS table as below: >> >> SELECT * FROM incidents >> WHERE urgency = 'Immediate' >> AND date_time_of_arrival - date_time_unit_assigned > '00:12:00' >> >> This gives me 33 points in QGIS. Great. I would now however like to >> save this as a ShapeFile for use in ArcGIS with which I am more >> familiar, but when I try to SAVE AS from QGIS I am given the following >> error >> >> Export to vector file failed. >> Error: trimming attribute name 'date_time_of_arrival' to ten >> significant characters produces duplicate column name. >> >> I am guessing that the problem here is that ESRI shapefiles can only >> deal with column names that are ten characters long...? And that as I >> also have a column called 'date_time_of_departure', when QGIS trims >> this column it ends up with two columns called the same thing? Is >> there a way around this? I realise I could rename the column in QGIS, >> but I actually have around 45 columns in the table and this problem >> will occur with about 15 pairs of them I think. I guess there is no >> simple answer... but thought I'd ask. >> >> Cheers >> >> James >> ___ >> postgis-users mailing list >> postgis-users@postgis.refractions.net >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> > ___ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users > ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction
This is what is really cool about using a database to store your data... Change your query to: SELECT mycol1, mycol2, date_time_of_arrival as dt_arrive, date_time_of_departure as dt_depart, the_geom FROM incidents WHERE urgency = 'Immediate' AND date_time_of_arrival - date_time_unit_assigned > '00:12:00' Note: you will need to specify the names of the columns that you are interested in. On Wed, Jun 15, 2011 at 12:58 PM, James David Smith wrote: > Dear all, > > I appreciate that this is more of a QGIS query, but I think that the > route of the problem might be in PostGIS, so... I have opened QGIS and > ran the query on my PostGIS table as below: > > SELECT * FROM incidents > WHERE urgency = 'Immediate' > AND date_time_of_arrival - date_time_unit_assigned > '00:12:00' > > This gives me 33 points in QGIS. Great. I would now however like to > save this as a ShapeFile for use in ArcGIS with which I am more > familiar, but when I try to SAVE AS from QGIS I am given the following > error > > Export to vector file failed. > Error: trimming attribute name 'date_time_of_arrival' to ten > significant characters produces duplicate column name. > > I am guessing that the problem here is that ESRI shapefiles can only > deal with column names that are ten characters long...? And that as I > also have a column called 'date_time_of_departure', when QGIS trims > this column it ends up with two columns called the same thing? Is > there a way around this? I realise I could rename the column in QGIS, > but I actually have around 45 columns in the table and this problem > will occur with about 15 pairs of them I think. I guess there is no > simple answer... but thought I'd ask. > > Cheers > > James > ___ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users > ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] QGIS - PostGIS - ArcGIS Interaction
some ideas... - create a view with name column length as you want. - looking for software ziggis, with this you can connect arcmap to Postgres Geodatabase bye... Cristian O. www.digitalbee.cl On Wed, Jun 15, 2011 at 1:58 PM, James David Smith < james.david.sm...@gmail.com> wrote: > Dear all, > > I appreciate that this is more of a QGIS query, but I think that the > route of the problem might be in PostGIS, so... I have opened QGIS and > ran the query on my PostGIS table as below: > > SELECT * FROM incidents > WHERE urgency = 'Immediate' > AND date_time_of_arrival - date_time_unit_assigned > '00:12:00' > > This gives me 33 points in QGIS. Great. I would now however like to > save this as a ShapeFile for use in ArcGIS with which I am more > familiar, but when I try to SAVE AS from QGIS I am given the following > error > > Export to vector file failed. > Error: trimming attribute name 'date_time_of_arrival' to ten > significant characters produces duplicate column name. > > I am guessing that the problem here is that ESRI shapefiles can only > deal with column names that are ten characters long...? And that as I > also have a column called 'date_time_of_departure', when QGIS trims > this column it ends up with two columns called the same thing? Is > there a way around this? I realise I could rename the column in QGIS, > but I actually have around 45 columns in the table and this problem > will occur with about 15 pairs of them I think. I guess there is no > simple answer... but thought I'd ask. > > Cheers > > James > ___ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users > ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
[postgis-users] QGIS - PostGIS - ArcGIS Interaction
Dear all, I appreciate that this is more of a QGIS query, but I think that the route of the problem might be in PostGIS, so... I have opened QGIS and ran the query on my PostGIS table as below: SELECT * FROM incidents WHERE urgency = 'Immediate' AND date_time_of_arrival - date_time_unit_assigned > '00:12:00' This gives me 33 points in QGIS. Great. I would now however like to save this as a ShapeFile for use in ArcGIS with which I am more familiar, but when I try to SAVE AS from QGIS I am given the following error Export to vector file failed. Error: trimming attribute name 'date_time_of_arrival' to ten significant characters produces duplicate column name. I am guessing that the problem here is that ESRI shapefiles can only deal with column names that are ten characters long...? And that as I also have a column called 'date_time_of_departure', when QGIS trims this column it ends up with two columns called the same thing? Is there a way around this? I realise I could rename the column in QGIS, but I actually have around 45 columns in the table and this problem will occur with about 15 pairs of them I think. I guess there is no simple answer... but thought I'd ask. Cheers James ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] ST_Intersects
Thanks again.
I did the same but thought if there was any better way.
Regards,
Mahesh
On 15 June 2011 17:10, Paul Ramsey wrote:
> It seems to me that the only way out of this conundrum (people with
> "boxes" they drew on projected maps) is to provide some densification
> functions so they can force their geometries to be closer to what they
> want by filling in points. Both geometry and geography could use some
> densification routines.
>
> P.
>
> On Tue, Jun 14, 2011 at 2:11 AM, Mahesh Ghule
> wrote:
> > Thanks a bunch Paul.
> > I did arrive those findings after I posted the query.
> > Now I am thinking how to do what I want to do if I want the polygon to be
> > with the great circles in postgis.
> > Any pointers.
> > Regards,
> > Mahesh
> > On 13 June 2011 17:49, Paul Ramsey wrote:
> >>
> >> And relatedly, here's why Google Earth gives the wrong visual answer.
> >>
> >> http://blog.opengeo.org/2010/08/10/shape-of-a-polygon/
> >>
> >> P.
> >>
> >> On Mon, Jun 13, 2011 at 9:47 AM, Paul Ramsey
> wrote:
> >> > You're thinking in straight lines, not great circles. Here's what your
> >> > "box" actually looks like
> >> >
> >> >
> >> >
> http://www.gcmap.com/mapui?P=10N+170E-10N+0E%2C%0D%0A10N+170E-5N+170E%2C%0D%0A5N+170E-5N+0E%2C%0D%0A5N+0E-10N+0E&MS=wls&DU=mi
> >> >
> >> > I can see how that could hit your Russian foot print.
> >> >
> >> > P.
> >> >
> >> > On Mon, Jun 13, 2011 at 6:54 AM, Mahesh Ghule >
> >> > wrote:
> >> >> Hello Guys,
> >> >> After lot of head scratching I have decided to post this email.
> >> >> We have a PostGIS 1.5.1 on PostgreSQL 8.4
> >> >> select
> >> >>
> >> >>
> ST_AsText('010520E610010001020002009FAEEE586C8C5240029CDEC5FBF94D406B44300E2EDB5140D591239D81D14C40'::geography)
> >> >> as TextFootPrint,
> >> >>
> >> >>
> >> >>
>
> ST_Intersects('010520E610010001020002009FAEEE586C8C5240029CDEC5FBF94D406B44300E2EDB5140D591239D81D14C40'::geography,
> >> >> ST_GeographyFromText('POLYGON((0 10,170 10,170 5,0 5,0 10))')) as
> >> >> Intersects;
> >> >> yields following result
> >> >> TextFootPrint
> >> >> | Intersects
> >> >>
> >> >>
> ---
> >> >> MULTILINESTRING((74.194113 59.952996,71.424686 57.636768)) |
> >> >>t
> >> >>
> >> >> Which as I understand is not correct. The footprint is a line string
> >> >> somewhere over Russia and the Polygon is a band in north hemisphere
> >> >> just
> >> >> above equator.
> >> >> Also when I visualise the both geographies as KML in google earth I
> can
> >> >> see
> >> >> them thousands of miles apart.
> >> >> This is just one example footprint where I have tens of thousand more
> >> >> in my
> >> >> DB like this.
> >> >> Please help me understand what is going on?
> >> >>
> >> >> Regards,
> >> >> Mahesh
> >> >>
> >> >> ___
> >> >> postgis-users mailing list
> >> >> postgis-users@postgis.refractions.net
> >> >> http://postgis.refractions.net/mailman/listinfo/postgis-users
> >> >>
> >> >>
> >> >
> >> ___
> >> postgis-users mailing list
> >> postgis-users@postgis.refractions.net
> >> http://postgis.refractions.net/mailman/listinfo/postgis-users
> >
> >
> > ___
> > postgis-users mailing list
> > postgis-users@postgis.refractions.net
> > http://postgis.refractions.net/mailman/listinfo/postgis-users
> >
> >
> ___
> postgis-users mailing list
> postgis-users@postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users
>
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Re: [postgis-users] ST_ConvexHull with millions of records...
Of you have a relatively uniform primary key on the table just take every record mod 100 or something. P. On Wed, Jun 15, 2011 at 6:37 AM, Martin Ouellet wrote: > Hi, > > The ST_ConvexHull function generates exactly the geometry that I need to > get the area covered by each of my tables. By cons, some of > them have millions of records and the operation crash. > > Is there a way to generate a geometry using > the function ST_ConvexHull but by reducing the precision or by a > process of aggregation? > > The accuracy is not required in my case, only to get an idea of the scope of > data foreach table. > > regards, > > MartinO > ___ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users > > ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] ST_Intersects
It seems to me that the only way out of this conundrum (people with
"boxes" they drew on projected maps) is to provide some densification
functions so they can force their geometries to be closer to what they
want by filling in points. Both geometry and geography could use some
densification routines.
P.
On Tue, Jun 14, 2011 at 2:11 AM, Mahesh Ghule wrote:
> Thanks a bunch Paul.
> I did arrive those findings after I posted the query.
> Now I am thinking how to do what I want to do if I want the polygon to be
> with the great circles in postgis.
> Any pointers.
> Regards,
> Mahesh
> On 13 June 2011 17:49, Paul Ramsey wrote:
>>
>> And relatedly, here's why Google Earth gives the wrong visual answer.
>>
>> http://blog.opengeo.org/2010/08/10/shape-of-a-polygon/
>>
>> P.
>>
>> On Mon, Jun 13, 2011 at 9:47 AM, Paul Ramsey wrote:
>> > You're thinking in straight lines, not great circles. Here's what your
>> > "box" actually looks like
>> >
>> >
>> > http://www.gcmap.com/mapui?P=10N+170E-10N+0E%2C%0D%0A10N+170E-5N+170E%2C%0D%0A5N+170E-5N+0E%2C%0D%0A5N+0E-10N+0E&MS=wls&DU=mi
>> >
>> > I can see how that could hit your Russian foot print.
>> >
>> > P.
>> >
>> > On Mon, Jun 13, 2011 at 6:54 AM, Mahesh Ghule
>> > wrote:
>> >> Hello Guys,
>> >> After lot of head scratching I have decided to post this email.
>> >> We have a PostGIS 1.5.1 on PostgreSQL 8.4
>> >> select
>> >>
>> >> ST_AsText('010520E610010001020002009FAEEE586C8C5240029CDEC5FBF94D406B44300E2EDB5140D591239D81D14C40'::geography)
>> >> as TextFootPrint,
>> >>
>> >>
>> >> ST_Intersects('010520E610010001020002009FAEEE586C8C5240029CDEC5FBF94D406B44300E2EDB5140D591239D81D14C40'::geography,
>> >> ST_GeographyFromText('POLYGON((0 10,170 10,170 5,0 5,0 10))')) as
>> >> Intersects;
>> >> yields following result
>> >> TextFootPrint
>> >> | Intersects
>> >>
>> >> ---
>> >> MULTILINESTRING((74.194113 59.952996,71.424686 57.636768)) |
>> >> t
>> >>
>> >> Which as I understand is not correct. The footprint is a line string
>> >> somewhere over Russia and the Polygon is a band in north hemisphere
>> >> just
>> >> above equator.
>> >> Also when I visualise the both geographies as KML in google earth I can
>> >> see
>> >> them thousands of miles apart.
>> >> This is just one example footprint where I have tens of thousand more
>> >> in my
>> >> DB like this.
>> >> Please help me understand what is going on?
>> >>
>> >> Regards,
>> >> Mahesh
>> >>
>> >> ___
>> >> postgis-users mailing list
>> >> postgis-users@postgis.refractions.net
>> >> http://postgis.refractions.net/mailman/listinfo/postgis-users
>> >>
>> >>
>> >
>> ___
>> postgis-users mailing list
>> postgis-users@postgis.refractions.net
>> http://postgis.refractions.net/mailman/listinfo/postgis-users
>
>
> ___
> postgis-users mailing list
> postgis-users@postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users
>
>
___
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Re: [postgis-users] Viewer plugins of PostGIS --HELP
I have used RT SQL for the exact case that you have outlined. I have a vector 'grid' that I connect to a very large data set. It allows me to store the geometry in one place and then connect the features with the values for one analytical parameter for a particular date for visualization. I have also done a similar thing with MapServer. I have a simple Web app that passes parameters for the date and the analyte to MapServer, which writes the query, hits PostGIS, and then renders the image. David. On Wed, Jun 15, 2011 at 4:04 AM, Paolo Cavallini wrote: > Il giorno mer, 15/06/2011 alle 16.29 +0800, Ben Madin ha scritto: >> This may not help, but I guess I find QGIS quite simple for actually >> visualising data. Maybe not so good for complex queries. There are now >> a number of PostGIS plug-ins though. > > Confirmed. You can also run complex queries via the RT SQL layer plugin, > and others. > All the best. > -- > Paolo Cavallini: http://www.faunalia.it/pc > > ___ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users > ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] raster table extent
That did the trick, thanks. On 6/15/2011 9:51 AM, Pierre Racine wrote: If you imported all of your rasters with one raster2pgsql command the "extent" column in the "raster_column" table should correspond to the global extent. If you imported with many commands, added or deleted tiles afterward, "extent" is not up to date. You can play with the ST_Extent aggregate. SELECT ST_Extent(rast) FROM your table That would be the preferred way to get an uptodate extent. If it's slow, create an index on your raster column. Pierre -Original Message- From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users- boun...@postgis.refractions.net] On Behalf Of Stephen Crawford Sent: Tuesday, June 14, 2011 7:04 PM To: PostGIS Users Discussion Subject: [postgis-users] raster table extent Is there a function that can provide the extent for an entire raster table? I see there is BOX2D for each raster in a table, but how about the entire table? Basically I think I loaded my raster in a way that the extent isn't where it should be, but I'm having trouble proving it. Thanks, Steve ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users -- Stephen Crawford Center for Environmental Informatics The Pennsylvania State University src...@psu.edu 814.865.9905 ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Basic postgis raster questions
> >I may be missing the boat here, but it seems to me that a version of > >ST_Intersection() which returns a raster would eliminate the need for a > >separate geometry parameter, and would be more in line with the spirit > >of "seamless vector/raster" processing. It also would seem that your > >separate geometry parameter would behave very much like a > >raster-returning ST_Intersection(), except that it is only usable > >"vicariously" via > the stats functions. > > Right. It would even be of greater value for other functionalities even if, I > think, > it would be slower for the particular case of computing stats . Sorry but I must come back on this. This is true when the vector area is small in comparison with the raster area AND if the raster coverage is tiled. In this case vectorization is possible and provide results very fast. This is true also if the raster is not tiled but is small. This operation provide very precise numbers because the intersection is done in vector mode and every pixel are cut when necessary. What you get is not a mere count of the pixels intersecting "a la Starspan" but true areas. In the other case (if the vector area is big in comparison the raster area OR the raster is big and not tiled) the all vector method is catastrophic as you have to vectorize many time large parts of the raster and this become unpracticable. This is why we need a pixel counter (ST_Histogram) accepting geometries. The provided result are somewhat coarser (take all the pixel or nothing) and provide a "a la Starspan" result, but at last, provide a result in reasonable time. This is why we need ST_Histogram, ST_SummaryStat, etc., accepting a geometry as parameter. Pierre ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] raster table extent
If you imported all of your rasters with one raster2pgsql command the "extent" column in the "raster_column" table should correspond to the global extent. If you imported with many commands, added or deleted tiles afterward, "extent" is not up to date. You can play with the ST_Extent aggregate. SELECT ST_Extent(rast) FROM your table That would be the preferred way to get an uptodate extent. If it's slow, create an index on your raster column. Pierre > -Original Message- > From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users- > boun...@postgis.refractions.net] On Behalf Of Stephen Crawford > Sent: Tuesday, June 14, 2011 7:04 PM > To: PostGIS Users Discussion > Subject: [postgis-users] raster table extent > > Is there a function that can provide the extent for an entire raster table? > I see > there is BOX2D for each raster in a table, but how about the entire table? > Basically I think I loaded my raster in a way that the extent isn't where it > should > be, but I'm having trouble proving it. > > Thanks, > Steve > > > ___ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
[postgis-users] ST_ConvexHull with millions of records...
Hi, The ST_ConvexHull function generates exactly the geometry that I need to get the area covered by each of my tables. By cons, some of them have millions of records and the operation crash. Is there a way to generate a geometry using the function ST_ConvexHull but by reducing the precision or by a process of aggregation? The accuracy is not required in my case, only to get an idea of the scope of data foreach table. regards, MartinO ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Viewer plugins of PostGIS --HELP
Il giorno mer, 15/06/2011 alle 11.05 +0100, James David Smith ha scritto: > Can you give me more information about the 'RT SQL layer plugin' you > mention please? I use GQIS to visualise my data from PostGIS > sometimes, but do find the query tool a bit limited and wonder whether > this might be the solution...? The plugin enables users without permissions (other than SELECT) to build their queries and to save them client-side. You should not have any major limitation. Please let us know how it goes. All the best. -- Paolo Cavallini: http://www.faunalia.it/pc ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
[postgis-users] Constrained Delaunay Triangulation
Hi, Could you please let me know how constrained delunay triangulation is implemented through GEOS? Sanjeewa ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Viewer plugins of PostGIS --HELP
Dear Paolo, Can you give me more information about the 'RT SQL layer plugin' you mention please? I use GQIS to visualise my data from PostGIS sometimes, but do find the query tool a bit limited and wonder whether this might be the solution...? Thanks James On 15 June 2011 10:04, Paolo Cavallini wrote: > Il giorno mer, 15/06/2011 alle 16.29 +0800, Ben Madin ha scritto: >> This may not help, but I guess I find QGIS quite simple for actually >> visualising data. Maybe not so good for complex queries. There are now >> a number of PostGIS plug-ins though. > > Confirmed. You can also run complex queries via the RT SQL layer plugin, > and others. > All the best. > -- > Paolo Cavallini: http://www.faunalia.it/pc > > ___ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users > ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Viewer plugins of PostGIS --HELP
Il giorno mer, 15/06/2011 alle 16.29 +0800, Ben Madin ha scritto: > This may not help, but I guess I find QGIS quite simple for actually > visualising data. Maybe not so good for complex queries. There are now > a number of PostGIS plug-ins though. Confirmed. You can also run complex queries via the RT SQL layer plugin, and others. All the best. -- Paolo Cavallini: http://www.faunalia.it/pc ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Viewer plugins of PostGIS --HELP
Ben, I know that the qGIS - OpenJump - uDig are very good solutions for visualizing the spatial data of postgis, but.. i want to try and explore these plug-ins. Anyway, thanks for your reply! Apostolis ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
Re: [postgis-users] Viewer plugins of PostGIS --HELP
Apostolis, This may not help, but I guess I find QGIS quite simple for actually visualising data. Maybe not so good for complex queries. There are now a number of PostGIS plug-ins though. Download. Install. Run. Add PostGIS Layer... cheers Ben On 15/06/2011, at 4:19 PM, ΑΠΟΣΤΟΛΟΣ ΛΕΛΕΝΤΖΗΣ wrote: > Hi list > > For another time, i ask your help and your valuable experience!! > My problem is related with ad-hoc solutions for viewing spatial data of a > postgis database. > I was searching a lot in the internet, and i found the following links which > indicate the installation and the usability of a postgis-viewer plugin. > > [1] > http://www.postgresonline.com/journal/archives/180-pgAdmin113plugins_postgis.html > [2] > http://geotux.tuxfamily.org/index.php?option=com_myblog&task=view&id=277&Itemid=59&lang=en > > Regarding with the first plugin[1], i have execute all the necessary guides > for the installation, but it doesn't work. > Specifically, i select a geometric table or i type a spatial SQL query, but > when i switch the postgis viewer then the new window don't visualize the > relevant table or the spatial outputs. > So, could anyone help me?? Maybe, someone else has used this tool?? > > Concerning with the second plugin [2], i have installed it, very easy and > quickly, but it doesn't work because it requires the installation of OSGeo4W > environment. > The postgis_viewer.bat file contains some variables which correspond to > OSGeo4W paths. Because, i have installed seperate all these programs which > are contained at OSGeo4W, i must change these paths for the good operation > of plugin. So, could anyone to show me how to configure the > postgis_viewer.bat file??? > > Any suggestion is accepted! > Thanks in advance > > Apostolis > ___ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
[postgis-users] Viewer plugins of PostGIS --HELP
Hi list For another time, i ask your help and your valuable experience!! My problem is related with ad-hoc solutions for viewing spatial data of a postgis database. I was searching a lot in the internet, and i found the following links which indicate the installation and the usability of a postgis-viewer plugin. [1] http://www.postgresonline.com/journal/archives/180-pgAdmin113plugins_postgis.html [2] http://geotux.tuxfamily.org/index.php?option=com_myblog&task=view&id=277&Itemid=59&lang=en Regarding with the first plugin[1], i have execute all the necessary guides for the installation, but it doesn't work. Specifically, i select a geometric table or i type a spatial SQL query, but when i switch the postgis viewer then the new window don't visualize the relevant table or the spatial outputs. So, could anyone help me?? Maybe, someone else has used this tool?? Concerning with the second plugin [2], i have installed it, very easy and quickly, but it doesn't work because it requires the installation of OSGeo4W environment. The postgis_viewer.bat file contains some variables which correspond to OSGeo4W paths. Because, i have installed seperate all these programs which are contained at OSGeo4W, i must change these paths for the good operation of plugin. So, could anyone to show me how to configure the postgis_viewer.bat file??? Any suggestion is accepted! Thanks in advance Apostolis ___ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
