Re: [datameet] Re: Query about the 2011 Districts shapefile
Dear Devdatta, OK. I wonder why I get 531/641 matches if the codes do not have the SAME meaning in both (the map and the lgdirectory ) datasets. What about ST_CEN_CD and DT_CEN_CD in the 2001 / 2011 Districts shapefiles ? Are those BOTH the Census codes for States and Districts respectively in 2001 ? I wish someone wrote a README explaining the column names in 2001/2011 Districts and States shapefiles. Best, Ashim On Wed, Dec 8, 2021 at 3:12 PM Devdatta Tengshe wrote: > > When this data was created, the Census Tables were not available, and it was > created by digitising the maps given in the Administrative Atlas PDF > available on the Census Website. > > So it included only the numbers available in the Administrative Atlas, and > not the actual codes that are available in the CENSUS Tables. > > Source: I was part of the India-WRIS team which had created this data. > > Regards, > Devdatta > > > On Wed, 8 Dec 2021 at 14:49, Ashim Kapoor wrote: >> >> Dear Devdatta, >> >> Many thanks for your reply. >> >> The website: >> >> https://lgdirectory.gov.in >> >> has Census 2001, Census 2011 codes for ALL Districts of India. >> >> Example on this website: >> >> For the State of Maharashtra, the districts Ahmednagar, Akola and >> Amrawati have Census 2011 codes = 522,501,503. >> >> In the 2011 shapefile the `censuscodes` for 522,501,503 correspond to >> Districts Ahmadnagar, Akola Amrawati. >> >> I have done a "outer join" of District names by >> censuscode=Census2011.Code and I get 531 / 641 matches. >> >> Please see the attached text file. I do not think this is happening by >> "chance". I do think that the censuscodes column in the 2011 Districts >> shapefile is the Census 2011 codes for Districts. >> >> Best, >> Ashim >> >> On Wed, Dec 8, 2021 at 1:47 PM Devdatta Tengshe wrote: >> > >> > The 'censuscode' is just a sequential ID, going from 0 (for POK Areas) to >> > 640. >> > >> > As far as I know, it has nothing to do with either the 2001 Census code or >> > 2011 Census. >> > >> > >> > >> > >> > Regards, >> > Devdatta >> > >> > >> > On Wed, 8 Dec 2021 at 12:35, Ashim Kapoor wrote: >> >> >> >> Dear All, >> >> >> >> I was a little confused. >> >> >> >> Attached are the extracts from 2001 / 2011 shapefiles as snippet. >> >> >> >> I think censuscode in 2011 shapefile = Census 2011 code for a District. >> >> I further think DT_CEN_CD in 2011 OR 2011 shapefiles = Census 2001 >> >> code for a District. >> >> >> >> I would like to confirm this. >> >> >> >> Best, >> >> Ashim >> >> >> >> 8<-snippet>8- >> >> >> >> > st_read("Census_2011/2011_Dist.shp") %>% filter(DISTRICT=="Ahmadnagar") >> >> Reading layer `2011_Dist' from data source >> >> >> >> `/home/ashim/Documents/my-workspace/space-to-verify-state-census-codes-from-districts-shapefile/maps/Districts/Census_2011/2011_Dist.shp' >> >> using driver `ESRI Shapefile' >> >> Simple feature collection with 641 features and 5 fields >> >> Geometry type: MULTIPOLYGON >> >> Dimension: XY >> >> Bounding box: xmin: 68.18625 ymin: 6.755953 xmax: 97.41529 ymax: 37.07827 >> >> CRS: 4326 >> >> Simple feature collection with 1 feature and 5 fields >> >> Geometry type: MULTIPOLYGON >> >> Dimension: XY >> >> Bounding box: xmin: 73.62021 ymin: 18.33075 xmax: 75.58884 ymax: 19.98771 >> >> CRS: 4326 >> >> DISTRICT ST_NM ST_CEN_CD DT_CEN_CD censuscode >> >> 1 Ahmadnagar Maharashtra2726522 >> >> geometry >> >> 1 MULTIPOLYGON (((74.67333 19... >> >> > st_read("Census_2001/2001_Dist.shp") %>% filter(DISTRICT=="Ahmadnagar") >> >> Reading layer `2001_Dist' from data source >> >> >> >> `/home/ashim/Documents/my-workspace/space-to-verify-state-census-codes-from-districts-shapefile/maps/Districts/Census_2001/2001_Dist.shp' >> >> using driver `ESRI Shapefile' >> >> Simple feature collection with 594 features and 4 fields >> >> Geometry type: MULTIPOLYGON >> >> Dimension: XY >> >> Bounding
Re: [datameet] Re: Query about the 2011 Districts shapefile
Dear Devdatta, Many thanks for your reply. The website: https://lgdirectory.gov.in has Census 2001, Census 2011 codes for ALL Districts of India. Example on this website: For the State of Maharashtra, the districts Ahmednagar, Akola and Amrawati have Census 2011 codes = 522,501,503. In the 2011 shapefile the `censuscodes` for 522,501,503 correspond to Districts Ahmadnagar, Akola Amrawati. I have done a "outer join" of District names by censuscode=Census2011.Code and I get 531 / 641 matches. Please see the attached text file. I do not think this is happening by "chance". I do think that the censuscodes column in the 2011 Districts shapefile is the Census 2011 codes for Districts. Best, Ashim On Wed, Dec 8, 2021 at 1:47 PM Devdatta Tengshe wrote: > > The 'censuscode' is just a sequential ID, going from 0 (for POK Areas) to 640. > > As far as I know, it has nothing to do with either the 2001 Census code or > 2011 Census. > > > > > Regards, > Devdatta > > > On Wed, 8 Dec 2021 at 12:35, Ashim Kapoor wrote: >> >> Dear All, >> >> I was a little confused. >> >> Attached are the extracts from 2001 / 2011 shapefiles as snippet. >> >> I think censuscode in 2011 shapefile = Census 2011 code for a District. >> I further think DT_CEN_CD in 2011 OR 2011 shapefiles = Census 2001 >> code for a District. >> >> I would like to confirm this. >> >> Best, >> Ashim >> >> 8<-snippet>8- >> >> > st_read("Census_2011/2011_Dist.shp") %>% filter(DISTRICT=="Ahmadnagar") >> Reading layer `2011_Dist' from data source >> >> `/home/ashim/Documents/my-workspace/space-to-verify-state-census-codes-from-districts-shapefile/maps/Districts/Census_2011/2011_Dist.shp' >> using driver `ESRI Shapefile' >> Simple feature collection with 641 features and 5 fields >> Geometry type: MULTIPOLYGON >> Dimension: XY >> Bounding box: xmin: 68.18625 ymin: 6.755953 xmax: 97.41529 ymax: 37.07827 >> CRS: 4326 >> Simple feature collection with 1 feature and 5 fields >> Geometry type: MULTIPOLYGON >> Dimension: XY >> Bounding box: xmin: 73.62021 ymin: 18.33075 xmax: 75.58884 ymax: 19.98771 >> CRS: 4326 >> DISTRICT ST_NM ST_CEN_CD DT_CEN_CD censuscode >> 1 Ahmadnagar Maharashtra2726522 >> geometry >> 1 MULTIPOLYGON (((74.67333 19... >> > st_read("Census_2001/2001_Dist.shp") %>% filter(DISTRICT=="Ahmadnagar") >> Reading layer `2001_Dist' from data source >> >> `/home/ashim/Documents/my-workspace/space-to-verify-state-census-codes-from-districts-shapefile/maps/Districts/Census_2001/2001_Dist.shp' >> using driver `ESRI Shapefile' >> Simple feature collection with 594 features and 4 fields >> Geometry type: MULTIPOLYGON >> Dimension: XY >> Bounding box: xmin: 68.18625 ymin: 6.755953 xmax: 97.41529 ymax: 37.07827 >> CRS: 4326 >> Simple feature collection with 1 feature and 4 fields >> Geometry type: MULTIPOLYGON >> Dimension: XY >> Bounding box: xmin: 73.62021 ymin: 18.33075 xmax: 75.58884 ymax: 19.98771 >> CRS: 4326 >> ST_NM ST_CEN_CD DT_CEN_CD DISTRICT geometry >> 1 Maharashtra2726 Ahmadnagar MULTIPOLYGON (((74.67333 19... >> > >> >> On Wed, Dec 8, 2021 at 11:18 AM Ashim Kapoor wrote: >> > >> > Deall All, >> > >> > I am working with the Districts shapefile using R. >> > >> > The file is located here: >> > >> > https://github.com/datameet/maps/tree/master/Districts >> > >> > Here are some records from this shapefile: >> > >> > > districts.map.with.crs %>% head >> > Simple feature collection with 6 features and 5 fields >> > Geometry type: MULTIPOLYGON >> > Dimension: XY >> > Bounding box: xmin: 71.60734 ymin: 18.33075 xmax: 93.20723 ymax: 27.40883 >> > CRS: EPSG:4326 >> > district st_nm st_cen_cd dt_cen_cd censuscode >> > 1 Adilabad Andhra Pradesh28 1532 >> > 2 Agra Uttar Pradesh 915146 >> > 3 AhmadabadGujarat24 7474 >> > 4 AhmadnagarMaharashtra2726522 >> > 5 AizawlMizoram15 3283 >> > 6 Ajmer Rajasthan 821119 >> >SHAPE >> > 1 MULT
[datameet] Re: Query about the 2011 Districts shapefile
Dear All, I was a little confused. Attached are the extracts from 2001 / 2011 shapefiles as snippet. I think censuscode in 2011 shapefile = Census 2011 code for a District. I further think DT_CEN_CD in 2011 OR 2011 shapefiles = Census 2001 code for a District. I would like to confirm this. Best, Ashim 8<-snippet>8- > st_read("Census_2011/2011_Dist.shp") %>% filter(DISTRICT=="Ahmadnagar") Reading layer `2011_Dist' from data source `/home/ashim/Documents/my-workspace/space-to-verify-state-census-codes-from-districts-shapefile/maps/Districts/Census_2011/2011_Dist.shp' using driver `ESRI Shapefile' Simple feature collection with 641 features and 5 fields Geometry type: MULTIPOLYGON Dimension: XY Bounding box: xmin: 68.18625 ymin: 6.755953 xmax: 97.41529 ymax: 37.07827 CRS: 4326 Simple feature collection with 1 feature and 5 fields Geometry type: MULTIPOLYGON Dimension: XY Bounding box: xmin: 73.62021 ymin: 18.33075 xmax: 75.58884 ymax: 19.98771 CRS: 4326 DISTRICT ST_NM ST_CEN_CD DT_CEN_CD censuscode 1 Ahmadnagar Maharashtra2726522 geometry 1 MULTIPOLYGON (((74.67333 19... > st_read("Census_2001/2001_Dist.shp") %>% filter(DISTRICT=="Ahmadnagar") Reading layer `2001_Dist' from data source `/home/ashim/Documents/my-workspace/space-to-verify-state-census-codes-from-districts-shapefile/maps/Districts/Census_2001/2001_Dist.shp' using driver `ESRI Shapefile' Simple feature collection with 594 features and 4 fields Geometry type: MULTIPOLYGON Dimension: XY Bounding box: xmin: 68.18625 ymin: 6.755953 xmax: 97.41529 ymax: 37.07827 CRS: 4326 Simple feature collection with 1 feature and 4 fields Geometry type: MULTIPOLYGON Dimension: XY Bounding box: xmin: 73.62021 ymin: 18.33075 xmax: 75.58884 ymax: 19.98771 CRS: 4326 ST_NM ST_CEN_CD DT_CEN_CD DISTRICT geometry 1 Maharashtra2726 Ahmadnagar MULTIPOLYGON (((74.67333 19... > On Wed, Dec 8, 2021 at 11:18 AM Ashim Kapoor wrote: > > Deall All, > > I am working with the Districts shapefile using R. > > The file is located here: > > https://github.com/datameet/maps/tree/master/Districts > > Here are some records from this shapefile: > > > districts.map.with.crs %>% head > Simple feature collection with 6 features and 5 fields > Geometry type: MULTIPOLYGON > Dimension: XY > Bounding box: xmin: 71.60734 ymin: 18.33075 xmax: 93.20723 ymax: 27.40883 > CRS: EPSG:4326 > district st_nm st_cen_cd dt_cen_cd censuscode > 1 Adilabad Andhra Pradesh28 1532 > 2 Agra Uttar Pradesh 915146 > 3 AhmadabadGujarat24 7474 > 4 AhmadnagarMaharashtra2726522 > 5 AizawlMizoram15 3283 > 6 Ajmer Rajasthan 821119 >SHAPE > 1 MULTIPOLYGON (((78.84972 19... > 2 MULTIPOLYGON (((78.19803 27... > 3 MULTIPOLYGON (((72.03456 23... > 4 MULTIPOLYGON (((74.67333 19... > 5 MULTIPOLYGON (((92.98749 24... > 6 MULTIPOLYGON (((74.89253 26... > > > > I have a question: > > In the Districts shapefile: > > st_cen_cd is the 2011 census code for States. > dt_cen_cd is the 2011 census code for Districts. > censuscode is the 2001 census code for Districts. > > Is the above correct? Especially the censuscode. Is it the 2001 census > code for a District? Is this mentioned somewhere ? > > Many thanks, > Ashim -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/datameet/CAC8%3D1eoNrTUkrKUWNUO67904wqR4qo1kzEYk319ZYQ2%2Bkez3nQ%40mail.gmail.com.
[datameet] Query about the 2011 Districts shapefile
Deall All, I am working with the Districts shapefile using R. The file is located here: https://github.com/datameet/maps/tree/master/Districts Here are some records from this shapefile: > districts.map.with.crs %>% head Simple feature collection with 6 features and 5 fields Geometry type: MULTIPOLYGON Dimension: XY Bounding box: xmin: 71.60734 ymin: 18.33075 xmax: 93.20723 ymax: 27.40883 CRS: EPSG:4326 district st_nm st_cen_cd dt_cen_cd censuscode 1 Adilabad Andhra Pradesh28 1532 2 Agra Uttar Pradesh 915146 3 AhmadabadGujarat24 7474 4 AhmadnagarMaharashtra2726522 5 AizawlMizoram15 3283 6 Ajmer Rajasthan 821119 SHAPE 1 MULTIPOLYGON (((78.84972 19... 2 MULTIPOLYGON (((78.19803 27... 3 MULTIPOLYGON (((72.03456 23... 4 MULTIPOLYGON (((74.67333 19... 5 MULTIPOLYGON (((92.98749 24... 6 MULTIPOLYGON (((74.89253 26... > I have a question: In the Districts shapefile: st_cen_cd is the 2011 census code for States. dt_cen_cd is the 2011 census code for Districts. censuscode is the 2001 census code for Districts. Is the above correct? Especially the censuscode. Is it the 2001 census code for a District? Is this mentioned somewhere ? Many thanks, Ashim -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/datameet/CAC8%3D1er_Jq3dopkiEyGF4EiknHHC260dphpo2eG6d-iBrex0Jw%40mail.gmail.com.
Re: [datameet] Re: Correct CRS for datameet maps
Dear Sharad, My apologies for the delay in responding.(The week was blissfully busy and I lost track of responding to this email). My response is inline. On Thu, Apr 18, 2019 at 11:09 PM Sharad Lele wrote: > Devdatta's summary was short and sweet, and practical. To add to it: > > 1. The NNRMS CRS suggested seems to be in Lambert Conformal Conic > projection (with WGS84 ellipsoid and datum). An alternative to it is the > UTM projection system, which keeps longitudes parallel, and gives > reasonably accurate area estimate. The particular UTM zone one may use > varies by which part of India one is in. > 2. In common parlance, 'unprojected' means having no Coordinate Reference > System at all. In GIS parlance, 'unprojected' may be understood as > 'geographic' CRS, that is, in lat-long rather than in metres. I presume > Ashim means 'having no CRS' at all. Whether one's map needs a CRS or not > depends upon what use one wants to put it to (and hence how accurate it > must be) and its size. A map of a 60'x40' piece of land does not require a > CRS if the purpose is house construction. It may require a CRS if one is > setting up a telescope on it which will do interferometry with another > telescope 500km away. A map of even a layout or a village or small town may > not need a CRS if one wants approximate locations/directions to navigate > visually (old style). It will need a CRS if one wants to use a GPS to > navigate. > If, Ashim, you mean 'geographic' vs 'projected' system, the answer is > different: geographic is useful for representation, easy to understand > (lat-long concept), but not to be used for calculating distances and areas. > I think when the data is "unprojected", it simply plots the points in a plane based on the co-ordinates( long / lat) . When it is projected it uses a transformation to go from points ( long / lat ) -> 2D map. > Hope this helps. Devdatta and others: please correct/supplement. > Sharad > > On Tuesday, April 16, 2019 at 3:38:08 PM UTC+5:30, Ashim wrote: >> >> Dear All, >> >> I have a small query on similar lines. When do we use UNPROJECTED maps ? >> I understand that to go from 3D to 2D we need a projection. When is it >> reasonable to use an unprojected map? >> >> Many thanks, >> Ashim >> >> On Tue, Apr 16, 2019 at 12:12 PM Ashim Kapoor wrote: >> >>> Dear Devdatta and Nikhil, >>> >>> I attended a R GIS school where the teachers were from France and they >>> were using CRS 2154. They told us that they were not familiar with the CRS >>> for Indian maps. >>> >>> I used 2154 thinking that it would not make much of a difference, but I >>> was wrong. My apologies for the confusion. When I used that on Indian ( >>> datameet ) shapefiles,I got this : map1.png ( see attachment ) >>> >>> I have also attached the R code to create these maps from the Datameet >>> District level ( 2011 ) shapefiles. I have created map2.png and map3.png >>> from crs = 3857 / 7755 respectively. >>> >>> I also found this : >>> https://epsg.io/?q=india >>> >>> Which is confusing because many CRS are there for India. Why do we have >>> so many choices of CRS for India ? >>> >>> I guess for the time being I will use 7755. >>> >>> Many thanks to Devdatta and Nikhil for their help. >>> Best Regards, >>> Ashim >>> >>> >>> >>> On Tue, Apr 16, 2019 at 11:42 AM Nikhil VJ wrote: >>> >>>> Hi Ashim, >>>> >>>> Pls provide the exact link of what you're referring - this stuff is >>>> never as much on the top of people's minds as we assume it to be. >>>> Do try loading your shapefiles on other tools and check there : >>>> mapshaper.org is a site that does a lot of quick, cool things with >>>> shapefiles; QGIS is a software that does everything with shapefiles. Both >>>> are free and open source. >>>> >>>> The latter will help you re-save the shapefile into any CRS you want. >>>> Right-click the layer > Save As (or "Export") and remember to choose your >>>> preferred CRS in the dropdown. >>>> >>>> Can you give background on what this CRS : *2154* : is and why you >>>> want to transform to that? Because I've only come across two main CRS's >>>> both being under the "WSG 84" category : >>>> - EPSG 4326 : this makes everything in latitude longitude >>>> - EPSG 3857 : this makes everything in meters from the equator (I >>>> think) and we ne
Re: [datameet] Re: Correct CRS for datameet maps
Dear All, I have a small query on similar lines. When do we use UNPROJECTED maps ? I understand that to go from 3D to 2D we need a projection. When is it reasonable to use an unprojected map? Many thanks, Ashim On Tue, Apr 16, 2019 at 12:12 PM Ashim Kapoor wrote: > Dear Devdatta and Nikhil, > > I attended a R GIS school where the teachers were from France and they > were using CRS 2154. They told us that they were not familiar with the CRS > for Indian maps. > > I used 2154 thinking that it would not make much of a difference, but I > was wrong. My apologies for the confusion. When I used that on Indian ( > datameet ) shapefiles,I got this : map1.png ( see attachment ) > > I have also attached the R code to create these maps from the Datameet > District level ( 2011 ) shapefiles. I have created map2.png and map3.png > from crs = 3857 / 7755 respectively. > > I also found this : > https://epsg.io/?q=india > > Which is confusing because many CRS are there for India. Why do we have so > many choices of CRS for India ? > > I guess for the time being I will use 7755. > > Many thanks to Devdatta and Nikhil for their help. > Best Regards, > Ashim > > > > On Tue, Apr 16, 2019 at 11:42 AM Nikhil VJ wrote: > >> Hi Ashim, >> >> Pls provide the exact link of what you're referring - this stuff is never >> as much on the top of people's minds as we assume it to be. >> Do try loading your shapefiles on other tools and check there : >> mapshaper.org is a site that does a lot of quick, cool things with >> shapefiles; QGIS is a software that does everything with shapefiles. Both >> are free and open source. >> >> The latter will help you re-save the shapefile into any CRS you want. >> Right-click the layer > Save As (or "Export") and remember to choose your >> preferred CRS in the dropdown. >> >> Can you give background on what this CRS : *2154* : is and why you want >> to transform to that? Because I've only come across two main CRS's both >> being under the "WSG 84" category : >> - EPSG 4326 : this makes everything in latitude longitude >> - EPSG 3857 : this makes everything in meters from the equator (I think) >> and we need to get the data in this format when we want to do things in >> physical distance terms like making a 1km distance buffer or measuring areas >> >> I haven't learned GIS stuff from theory, I just use it, so don't know >> more details about CRS. I do understand that the dizzying multitude of >> CRS's out there are so because apparently GIS folks like to re-orient the >> center of the world (geometrically speaking) to where their data is to >> ensure least distortion of their shapes in the rendering. When I come >> across anything that's in a non-standard CRS, my first move is to transform >> it to either lat-longs (4326) or meters (3857). >> >> Regards >> Nikhil VJ >> >> >> On Monday, April 15, 2019 at 1:57:20 PM UTC+5:30, Ashim wrote: >>> >>> Dear All, >>> >>> I am referring to 2011_Dist. * set of shapefile. (District level >>> shapefiles). >>> >>> When I read them as simple features in R, ( like this ) >>> >>> map <- st_read("2011_Dist.shp") %>% st_as_sf() >>> >>> ( it's unprojected because it says 4326 in the epsg when I read the >>> above ) >>> >>> plot(map$geometry) >>> >>> it looks OK. >>> >>> But when I do : >>> >>> map <- st_read("2011_Dist.shp") %>% st_as_sf() %>% st_transform(crs= >>> 2154) >>> >>> plot(map$geometry) >>> >>> the map is TILTED. >>> >>> What is the correct projection to use for this dataset? Please clarify. >>> >>> Best Regards, >>> Ashim >>> >> -- >> Datameet is a community of Data Science enthusiasts in India. Know more >> about us by visiting http://datameet.org >> --- >> You received this message because you are subscribed to the Google Groups >> "datameet" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to datameet+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [datameet] Re: Correct CRS for datameet maps
Dear Devdatta and Nikhil, I attended a R GIS school where the teachers were from France and they were using CRS 2154. They told us that they were not familiar with the CRS for Indian maps. I used 2154 thinking that it would not make much of a difference, but I was wrong. My apologies for the confusion. When I used that on Indian ( datameet ) shapefiles,I got this : map1.png ( see attachment ) I have also attached the R code to create these maps from the Datameet District level ( 2011 ) shapefiles. I have created map2.png and map3.png from crs = 3857 / 7755 respectively. I also found this : https://epsg.io/?q=india Which is confusing because many CRS are there for India. Why do we have so many choices of CRS for India ? I guess for the time being I will use 7755. Many thanks to Devdatta and Nikhil for their help. Best Regards, Ashim On Tue, Apr 16, 2019 at 11:42 AM Nikhil VJ wrote: > Hi Ashim, > > Pls provide the exact link of what you're referring - this stuff is never > as much on the top of people's minds as we assume it to be. > Do try loading your shapefiles on other tools and check there : > mapshaper.org is a site that does a lot of quick, cool things with > shapefiles; QGIS is a software that does everything with shapefiles. Both > are free and open source. > > The latter will help you re-save the shapefile into any CRS you want. > Right-click the layer > Save As (or "Export") and remember to choose your > preferred CRS in the dropdown. > > Can you give background on what this CRS : *2154* : is and why you want > to transform to that? Because I've only come across two main CRS's both > being under the "WSG 84" category : > - EPSG 4326 : this makes everything in latitude longitude > - EPSG 3857 : this makes everything in meters from the equator (I think) > and we need to get the data in this format when we want to do things in > physical distance terms like making a 1km distance buffer or measuring areas > > I haven't learned GIS stuff from theory, I just use it, so don't know more > details about CRS. I do understand that the dizzying multitude of CRS's out > there are so because apparently GIS folks like to re-orient the center of > the world (geometrically speaking) to where their data is to ensure least > distortion of their shapes in the rendering. When I come across anything > that's in a non-standard CRS, my first move is to transform it to either > lat-longs (4326) or meters (3857). > > Regards > Nikhil VJ > > > On Monday, April 15, 2019 at 1:57:20 PM UTC+5:30, Ashim wrote: >> >> Dear All, >> >> I am referring to 2011_Dist. * set of shapefile. (District level >> shapefiles). >> >> When I read them as simple features in R, ( like this ) >> >> map <- st_read("2011_Dist.shp") %>% st_as_sf() >> >> ( it's unprojected because it says 4326 in the epsg when I read the above >> ) >> >> plot(map$geometry) >> >> it looks OK. >> >> But when I do : >> >> map <- st_read("2011_Dist.shp") %>% st_as_sf() %>% st_transform(crs= 2154) >> >> plot(map$geometry) >> >> the map is TILTED. >> >> What is the correct projection to use for this dataset? Please clarify. >> >> Best Regards, >> Ashim >> > -- > Datameet is a community of Data Science enthusiasts in India. Know more > about us by visiting http://datameet.org > --- > You received this message because you are subscribed to the Google Groups > "datameet" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to datameet+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. map.R Description: Binary data
[datameet] Correct CRS for datameet maps
Dear All, I am referring to 2011_Dist. * set of shapefile. (District level shapefiles). When I read them as simple features in R, ( like this ) map <- st_read("2011_Dist.shp") %>% st_as_sf() ( it's unprojected because it says 4326 in the epsg when I read the above ) plot(map$geometry) it looks OK. But when I do : map <- st_read("2011_Dist.shp") %>% st_as_sf() %>% st_transform(crs= 2154) plot(map$geometry) the map is TILTED. What is the correct projection to use for this dataset? Please clarify. Best Regards, Ashim -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [datameet] Rural vs urban areas in India
Dear Arun, Many thanks for your prompt reply. One person here says it's commercially available from GIS vendors:- https://www.quora.com/Maps-Where-we-can-find-the-list-of-all-villages-of-India-with-their-longitude-and-latitude I will explore the data set that you have suggested. Best Regards, Ashim On Wed, Jan 16, 2019 at 5:59 PM Arun Ganesh wrote: > You got lucky, i just happened to be looking for this an hour ago. > > You can use the data from Global Human Settlement dataset Settlement Grid: > https://ghsl.jrc.ec.europa.eu/datasets.php > > Its a gridded raster tif where each pixel has a value for urbanization. If > you load it into qgis and use some python, you can classify an input set of > points if they are urban or rural. > > Dont know if theres a ready API already available that already offers this > as a service. > > -- > Datameet is a community of Data Science enthusiasts in India. Know more > about us by visiting http://datameet.org > --- > You received this message because you are subscribed to the Google Groups > "datameet" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to datameet+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[datameet] Rural vs urban areas in India
Dear all, Is there any way that given a lat long in India, we can classify it as rural / urban ? Best Regards, Ashim -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [datameet] States shapefile is based on which Census Year ?
Dear Devdatta. This page : http://projects.datameet.org/maps/districts/ says : The District Boundaries of India, Scraped from ECI's Poling Station Locations <http://psleci.nic.in/> Website. Wouldn’t the ECI website have the latest data on Districts? Since the Districts boundaries are scraped from ECI's website wouldn’t we have the latest Districts boundaries ? Where do I misunderstand ? Best Regards, Ashim On Fri, Apr 27, 2018 at 12:25 PM, Devdatta Tengshe <devda...@tengshe.in> wrote: > > we are approximately correct is using both the State and the District > shapefiles ? > > No! > The states represent the current boundaries, while the districts shapefile > represent the 2001 Census & 2011 Census. > > We do not have a District file for the Current boundaries & names. > > Regards, > Devdatta > > On Fri, Apr 27, 2018 at 12:22 PM, Ashim Kapoor <ashimkap...@gmail.com> > wrote: > >> Dear Devdatta, >> >> Thank you once again for the prompt reply. So if I understand correctly, >> we are approximately correct is using both the State and the District >> shapefiles ? >> >> Warm Regards, >> Ashim >> >> On Fri, Apr 27, 2018 at 12:13 PM, Devdatta Tengshe <devda...@tengshe.in> >> wrote: >> >>> Hi Ashim, >>> >>> Both those sections are incorrect. I've created a >>> https://github.com/datameet/maps/issues/28 for the same. >>> >>> The States folder at https://github.com/datameet/maps/ contains updated >>> State Boundries, while the District have information from 2011 & 2001 >>> Census. >>> >>> Regards, >>> Devdatta >>> >>> On Fri, Apr 27, 2018 at 11:53 AM, Ashim Kapoor <ashimkap...@gmail.com> >>> wrote: >>> >>>> Dear Devdatta, >>>> >>>> Many thanks for your reply. >>>> >>>> On this page: >>>> >>>> http://projects.datameet.org/maps/states/ >>>> >>>> Item 3 says : >>>> >>>> Some State Boundaries Names seem to be incorrect or Missing. >>>> >>>> Also on this page : >>>> >>>> http://projects.datameet.org/maps/districts/ >>>> >>>> Item 3 says : >>>> Some Assemblies Constituency Names seem to be incorrect or Missing. >>>> >>>> Can you please clarify which ones are these ? Is there a list of >>>> Incorrect/Missing States / Districts ? >>>> >>>> Best Regards, >>>> Ashim >>>> >>>> On Fri, Apr 27, 2018 at 11:31 AM, Devdatta Tengshe <devda...@tengshe.in >>>> > wrote: >>>> >>>>> This data was originally based on the 2011 Census; We have then >>>>> partitioned AP and also updated the Telangan Boundary based on the 2015 >>>>> Order. >>>>> >>>>> So this data approximately represents the current situation. >>>>> >>>>> Regards, >>>>> Devdatta >>>>> >>>>> On Fri, Apr 27, 2018 at 9:57 AM, Ashim Kapoor <ashimkap...@gmail.com> >>>>> wrote: >>>>> >>>>>> Dear all, >>>>>> >>>>>> I am referring to the State maps here : >>>>>> >>>>>> http://projects.datameet.org/maps/states/ >>>>>> >>>>>> My query is : what Census year is this based on ? Can someone clarify >>>>>> ? >>>>>> >>>>>> Best Regards, >>>>>> Ashim >>>>>> >>>>>> -- >>>>>> Datameet is a community of Data Science enthusiasts in India. Know >>>>>> more about us by visiting http://datameet.org >>>>>> --- >>>>>> You received this message because you are subscribed to the Google >>>>>> Groups "datameet" group. >>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>> send an email to datameet+unsubscr...@googlegroups.com. >>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>> >>>>> >>>>> -- >>>>> Datameet is a community of Data Science enthusiasts in India. Know >>>>> more about us by visiting http://datameet.org >>>>> --- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "datameet" group. &g
Re: [datameet] States shapefile is based on which Census Year ?
Dear Devdatta, Thank you once again for the prompt reply. So if I understand correctly, we are approximately correct is using both the State and the District shapefiles ? Warm Regards, Ashim On Fri, Apr 27, 2018 at 12:13 PM, Devdatta Tengshe <devda...@tengshe.in> wrote: > Hi Ashim, > > Both those sections are incorrect. I've created a > https://github.com/datameet/maps/issues/28 for the same. > > The States folder at https://github.com/datameet/maps/ contains updated > State Boundries, while the District have information from 2011 & 2001 > Census. > > Regards, > Devdatta > > On Fri, Apr 27, 2018 at 11:53 AM, Ashim Kapoor <ashimkap...@gmail.com> > wrote: > >> Dear Devdatta, >> >> Many thanks for your reply. >> >> On this page: >> >> http://projects.datameet.org/maps/states/ >> >> Item 3 says : >> >> Some State Boundaries Names seem to be incorrect or Missing. >> >> Also on this page : >> >> http://projects.datameet.org/maps/districts/ >> >> Item 3 says : >> Some Assemblies Constituency Names seem to be incorrect or Missing. >> >> Can you please clarify which ones are these ? Is there a list of >> Incorrect/Missing States / Districts ? >> >> Best Regards, >> Ashim >> >> On Fri, Apr 27, 2018 at 11:31 AM, Devdatta Tengshe <devda...@tengshe.in> >> wrote: >> >>> This data was originally based on the 2011 Census; We have then >>> partitioned AP and also updated the Telangan Boundary based on the 2015 >>> Order. >>> >>> So this data approximately represents the current situation. >>> >>> Regards, >>> Devdatta >>> >>> On Fri, Apr 27, 2018 at 9:57 AM, Ashim Kapoor <ashimkap...@gmail.com> >>> wrote: >>> >>>> Dear all, >>>> >>>> I am referring to the State maps here : >>>> >>>> http://projects.datameet.org/maps/states/ >>>> >>>> My query is : what Census year is this based on ? Can someone clarify ? >>>> >>>> Best Regards, >>>> Ashim >>>> >>>> -- >>>> Datameet is a community of Data Science enthusiasts in India. Know more >>>> about us by visiting http://datameet.org >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "datameet" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to datameet+unsubscr...@googlegroups.com. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >>> Datameet is a community of Data Science enthusiasts in India. Know more >>> about us by visiting http://datameet.org >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "datameet" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to datameet+unsubscr...@googlegroups.com. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- >> Datameet is a community of Data Science enthusiasts in India. Know more >> about us by visiting http://datameet.org >> --- >> You received this message because you are subscribed to the Google Groups >> "datameet" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to datameet+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > > -- > Datameet is a community of Data Science enthusiasts in India. Know more > about us by visiting http://datameet.org > --- > You received this message because you are subscribed to the Google Groups > "datameet" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to datameet+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [datameet] States shapefile is based on which Census Year ?
Dear Devdatta, Many thanks for your reply. On this page: http://projects.datameet.org/maps/states/ Item 3 says : Some State Boundaries Names seem to be incorrect or Missing. Also on this page : http://projects.datameet.org/maps/districts/ Item 3 says : Some Assemblies Constituency Names seem to be incorrect or Missing. Can you please clarify which ones are these ? Is there a list of Incorrect/Missing States / Districts ? Best Regards, Ashim On Fri, Apr 27, 2018 at 11:31 AM, Devdatta Tengshe <devda...@tengshe.in> wrote: > This data was originally based on the 2011 Census; We have then > partitioned AP and also updated the Telangan Boundary based on the 2015 > Order. > > So this data approximately represents the current situation. > > Regards, > Devdatta > > On Fri, Apr 27, 2018 at 9:57 AM, Ashim Kapoor <ashimkap...@gmail.com> > wrote: > >> Dear all, >> >> I am referring to the State maps here : >> >> http://projects.datameet.org/maps/states/ >> >> My query is : what Census year is this based on ? Can someone clarify ? >> >> Best Regards, >> Ashim >> >> -- >> Datameet is a community of Data Science enthusiasts in India. Know more >> about us by visiting http://datameet.org >> --- >> You received this message because you are subscribed to the Google Groups >> "datameet" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to datameet+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > > -- > Datameet is a community of Data Science enthusiasts in India. Know more > about us by visiting http://datameet.org > --- > You received this message because you are subscribed to the Google Groups > "datameet" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to datameet+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[datameet] States shapefile is based on which Census Year ?
Dear all, I am referring to the State maps here : http://projects.datameet.org/maps/states/ My query is : what Census year is this based on ? Can someone clarify ? Best Regards, Ashim -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[datameet] 2011 Districts Shapefile seems to have an island inside Odisha
Dear All, I downloaded the shapefiles from : http://projects.datameet.org/maps/districts/ Then I subset it and kept only districts in Odisha and then took a union of all polygons in Odisha. When I did this I was expecting the boundary of Odisha. What I can see instead is the boundary of Odisha with a polygon inside it. Please see the attached code in R and the pdf generated by this code. I guess I can use the State shapefile for the state boundary of Odisha but I thought I would report this. Best Regards, Ashim -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. code.R Description: Binary data map.pdf Description: Adobe PDF document
[datameet] Creating a Indian law approved map of India using OSM
Dear All, I need to create a shapefile of India using OSM data which shows the Indian version of the borders according to the existing law. Can someone point me in the right direction ? Many thanks, Ashim -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [datameet] are these shapefiles based on OSM ?
Dear Arun, Thank you. Best Regards, Ashim On Thu, Nov 2, 2017 at 3:34 PM, Arun Ganesh <arungra...@gmail.com> wrote: > > > On Thu, Nov 2, 2017 at 8:06 AM, Ashim Kapoor <ashimkap...@gmail.com> > wrote: > >> Dear All, >> >> I am looking for OSM based shapefile of India at the state and district >> level. Can someone point me in the right direction? >> > > > You can generate a shapefile for any arbitrary area using > https://mapzen.com/data/metro-extracts/ > > If you want one for each district, your best bet is to do it > programmatically with postgres and QGIS. > > > -- > Datameet is a community of Data Science enthusiasts in India. Know more > about us by visiting http://datameet.org > --- > You received this message because you are subscribed to the Google Groups > "datameet" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to datameet+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[datameet] are these shapefiles based on OSM ?
Dear All, I have a query. Are the following shapefiles : http://datameet.org/indian-shapefiles-central/ based on open street map ? Please clarify. Best Regards, Ashim -- Datameet is a community of Data Science enthusiasts in India. Know more about us by visiting http://datameet.org --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to datameet+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.