Re: [GRASS-dev] Struggling using two layered vector maps with v.what.rast
Hi [snip] Not so hard ;) But with thousands of vector layers you could experience slowed down operations involving categories, slowed down exponentially with the number of layers. But maybe this only becomes an issue with hundreds of thousands of vector layers. Done in r50501 https://trac.osgeo.org/grass/changeset/50501 Best regards Soeren btw: * v.timestamp with layer support is in svn * Vector layer timestamp support in the temporal GIS implementation is in my local svn copy and needs more testing - i need to create vector maps with multiple categorized layer. For the time being, you could run v.category option=transfer in a loop. Markus M Additionally i need to timestamp the layer in the temporal database. It would be meaningful to timestamp layers at file level using v.timestamp too. An approach which i have in mind is to extent v.timestamp with a layer option, so that timetsamp text files can be created for each layer in the vector map directory. An application in the temporal GIS and for environmental modelling would be the observation of raster time series at specific vector point locations. The vector location do not change over time, but the attribute tables. Hence, for each observed time step a new timestamped layer and table will be added to the observation vector map and filled with raster values. i just started to investigate the new shiny world of multiple layer usage. I hope you enjoy it! I do. :) Best regards Soeren Markus M Best regards Soeren 2012/1/25 Martin Landa landa.mar...@gmail.com: Hi, db.copy from_table=soil to_table=soil_2 - makes copy of `soil` table v.db.addtable map=soil table=soil_2 layer=2 - it would overwrite `soil_2` table, but do nothing in this case, no feature have category defined in layer 2. Proposal: v.random --o -z seed=1 output=soil n=20 zmin=0 zmax=100 column=clay v.category input=soil out=soil2 option=transfer layer=1,2 --o db.copy from_table=soil to_table=soil_2 v.db.connect map=soil2 table=soil_2 layer=2 v.db.addcolumn map=soil2 layer=1 columns='sand_frac DOUBLE PRECISION' v.db.addcolumn map=soil2 layer=2 columns='sand_frac DOUBLE PRECISION' ... Martin -- Martin Landa landa.martin gmail.com * http://geo.fsv.cvut.cz/~landa ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev
Re: [GRASS-dev] Struggling using two layered vector maps with v.what.rast
Hi Martin, many thanks for your example. It works fine with two layer. But is there a way to add categories to a number of layers larger than two using the same vector map? Why is a full vector copy needed in case of category transfer from one to another layer? Sorry for my noobish questions, but i just started to investigate the new shiny world of multiple layer usage. Best regards Soeren 2012/1/25 Martin Landa landa.mar...@gmail.com: Hi, db.copy from_table=soil to_table=soil_2 - makes copy of `soil` table v.db.addtable map=soil table=soil_2 layer=2 - it would overwrite `soil_2` table, but do nothing in this case, no feature have category defined in layer 2. Proposal: v.random --o -z seed=1 output=soil n=20 zmin=0 zmax=100 column=clay v.category input=soil out=soil2 option=transfer layer=1,2 --o db.copy from_table=soil to_table=soil_2 v.db.connect map=soil2 table=soil_2 layer=2 v.db.addcolumn map=soil2 layer=1 columns='sand_frac DOUBLE PRECISION' v.db.addcolumn map=soil2 layer=2 columns='sand_frac DOUBLE PRECISION' ... Martin -- Martin Landa landa.martin gmail.com * http://geo.fsv.cvut.cz/~landa ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev
Re: [GRASS-dev] Struggling using two layered vector maps with v.what.rast
2012/1/25 Sören Gebbert soerengebb...@googlemail.com: Hi Martin, many thanks for your example. It works fine with two layer. But is there a way to add categories to a number of layers larger than two using the same vector map? This will add new categories to a new layer, irrespective of how many layers are already defined: v.category option=add Note that a GRASS layer is defined by the existence of at least one vector feature with at least one category value in that layer. That layer may or may not be attached to an attribute table. For examples, see v.in.ogr when importing several layers at once, the LiDAR filtering tools, or the vector output of r.stream.extract. Why is a full vector copy needed in case of category transfer from one to another layer? Because category transfer takes place in the vector feature, i.e. modifies the coor file of the vector. v.category option=transfer does not add an attribute table (AFAIK). i just started to investigate the new shiny world of multiple layer usage. I hope you enjoy it! Markus M Best regards Soeren 2012/1/25 Martin Landa landa.mar...@gmail.com: Hi, db.copy from_table=soil to_table=soil_2 - makes copy of `soil` table v.db.addtable map=soil table=soil_2 layer=2 - it would overwrite `soil_2` table, but do nothing in this case, no feature have category defined in layer 2. Proposal: v.random --o -z seed=1 output=soil n=20 zmin=0 zmax=100 column=clay v.category input=soil out=soil2 option=transfer layer=1,2 --o db.copy from_table=soil to_table=soil_2 v.db.connect map=soil2 table=soil_2 layer=2 v.db.addcolumn map=soil2 layer=1 columns='sand_frac DOUBLE PRECISION' v.db.addcolumn map=soil2 layer=2 columns='sand_frac DOUBLE PRECISION' ... Martin -- Martin Landa landa.martin gmail.com * http://geo.fsv.cvut.cz/~landa ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev
Re: [GRASS-dev] Struggling using two layered vector maps with v.what.rast
Hi Markus, thanks for your explanation. 2012/1/25 Markus Metz markus.metz.gisw...@googlemail.com: 2012/1/25 Sören Gebbert soerengebb...@googlemail.com: Hi Martin, many thanks for your example. It works fine with two layer. But is there a way to add categories to a number of layers larger than two using the same vector map? This will add new categories to a new layer, irrespective of how many layers are already defined: v.category option=add Note that a GRASS layer is defined by the existence of at least one vector feature with at least one category value in that layer. That layer may or may not be attached to an attribute table. For examples, see v.in.ogr when importing several layers at once, the LiDAR filtering tools, or the vector output of r.stream.extract. I will have a look. Why is a full vector copy needed in case of category transfer from one to another layer? Because category transfer takes place in the vector feature, i.e. modifies the coor file of the vector. v.category option=transfer does not add an attribute table (AFAIK). Maybe this function: off_t Vect_rewrite_line(struct Map_info *Map, int line, int type, const struct line_pnts *points, const struct line_cats *cats) can be used to add new layer using existing categories (from layer 1?) to an existing vector map? My problem is that i want to successively add new layers (tables) to existing vector maps using existing categories. Additionally i need to timestamp the layer in the temporal database. It would be meaningful to timestamp layers at file level using v.timestamp too. An approach which i have in mind is to extent v.timestamp with a layer option, so that timetsamp text files can be created for each layer in the vector map directory. An application in the temporal GIS and for environmental modelling would be the observation of raster time series at specific vector point locations. The vector location do not change over time, but the attribute tables. Hence, for each observed time step a new timestamped layer and table will be added to the observation vector map and filled with raster values. i just started to investigate the new shiny world of multiple layer usage. I hope you enjoy it! I do. :) Best regards Soeren Markus M Best regards Soeren 2012/1/25 Martin Landa landa.mar...@gmail.com: Hi, db.copy from_table=soil to_table=soil_2 - makes copy of `soil` table v.db.addtable map=soil table=soil_2 layer=2 - it would overwrite `soil_2` table, but do nothing in this case, no feature have category defined in layer 2. Proposal: v.random --o -z seed=1 output=soil n=20 zmin=0 zmax=100 column=clay v.category input=soil out=soil2 option=transfer layer=1,2 --o db.copy from_table=soil to_table=soil_2 v.db.connect map=soil2 table=soil_2 layer=2 v.db.addcolumn map=soil2 layer=1 columns='sand_frac DOUBLE PRECISION' v.db.addcolumn map=soil2 layer=2 columns='sand_frac DOUBLE PRECISION' ... Martin -- Martin Landa landa.martin gmail.com * http://geo.fsv.cvut.cz/~landa ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev
Re: [GRASS-dev] Struggling using two layered vector maps with v.what.rast
2012/1/25 Sören Gebbert soerengebb...@googlemail.com: 2012/1/25 Markus Metz markus.metz.gisw...@googlemail.com: Note that a GRASS layer is defined by the existence of at least one vector feature with at least one category value in that layer. That layer may or may not be attached to an attribute table. For examples, see v.in.ogr when importing several layers at once, the LiDAR filtering tools, or the vector output of r.stream.extract. I will have a look. Also the v.net.* modules, which make use of layers to distinguish between line and node costs with the help of layers. Why is a full vector copy needed in case of category transfer from one to another layer? Because category transfer takes place in the vector feature, i.e. modifies the coor file of the vector. v.category option=transfer does not add an attribute table (AFAIK). Maybe this function: off_t Vect_rewrite_line(struct Map_info *Map, int line, int type, const struct line_pnts *points, const struct line_cats *cats) can be used to add new layer using existing categories (from layer 1?) to an existing vector map? Adding a new layer always means adding new categories, also if they are identical to categories in a different layer. The difference between Vect_rewrite_line and the combination of Vect_delete_line, Vect_write_line is only that Vect_rewrite_line is supposed to check if the new line fits into the space used by the old line. My problem is that i want to successively add new layers (tables) to existing vector maps using existing categories. The problem is that the categories are not existing for a new layer because of the definition of a new layer. If there would be categories existing for that layer, the layer would already exist. I guess you must either use v.category option=transfer or have a bunch of tables but only one vector with one layer and disconnect/reconnect the tables as needed, only one table would then be connected to the vector at any given time. I have used that successfully for time series points some time ago, it's the fastest solution but needs some care in handling the tables. Probably not an option for the temporal database unless you want to introduce db.table.timestamp... Markus M Additionally i need to timestamp the layer in the temporal database. It would be meaningful to timestamp layers at file level using v.timestamp too. An approach which i have in mind is to extent v.timestamp with a layer option, so that timetsamp text files can be created for each layer in the vector map directory. An application in the temporal GIS and for environmental modelling would be the observation of raster time series at specific vector point locations. The vector location do not change over time, but the attribute tables. Hence, for each observed time step a new timestamped layer and table will be added to the observation vector map and filled with raster values. i just started to investigate the new shiny world of multiple layer usage. I hope you enjoy it! I do. :) Best regards Soeren Markus M Best regards Soeren 2012/1/25 Martin Landa landa.mar...@gmail.com: Hi, db.copy from_table=soil to_table=soil_2 - makes copy of `soil` table v.db.addtable map=soil table=soil_2 layer=2 - it would overwrite `soil_2` table, but do nothing in this case, no feature have category defined in layer 2. Proposal: v.random --o -z seed=1 output=soil n=20 zmin=0 zmax=100 column=clay v.category input=soil out=soil2 option=transfer layer=1,2 --o db.copy from_table=soil to_table=soil_2 v.db.connect map=soil2 table=soil_2 layer=2 v.db.addcolumn map=soil2 layer=1 columns='sand_frac DOUBLE PRECISION' v.db.addcolumn map=soil2 layer=2 columns='sand_frac DOUBLE PRECISION' ... Martin -- Martin Landa landa.martin gmail.com * http://geo.fsv.cvut.cz/~landa ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev
Re: [GRASS-dev] Struggling using two layered vector maps with v.what.rast
Hi Markus, 2012/1/25 Markus Metz markus.metz.gisw...@googlemail.com: 2012/1/25 Sören Gebbert soerengebb...@googlemail.com: 2012/1/25 Markus Metz markus.metz.gisw...@googlemail.com: Note that a GRASS layer is defined by the existence of at least one vector feature with at least one category value in that layer. That layer may or may not be attached to an attribute table. For examples, see v.in.ogr when importing several layers at once, the LiDAR filtering tools, or the vector output of r.stream.extract. I will have a look. Also the v.net.* modules, which make use of layers to distinguish between line and node costs with the help of layers. Why is a full vector copy needed in case of category transfer from one to another layer? Because category transfer takes place in the vector feature, i.e. modifies the coor file of the vector. v.category option=transfer does not add an attribute table (AFAIK). Maybe this function: off_t Vect_rewrite_line(struct Map_info *Map, int line, int type, const struct line_pnts *points, const struct line_cats *cats) can be used to add new layer using existing categories (from layer 1?) to an existing vector map? Adding a new layer always means adding new categories, also if they are identical to categories in a different layer. The difference between Vect_rewrite_line and the combination of Vect_delete_line, Vect_write_line is only that Vect_rewrite_line is supposed to check if the new line fits into the space used by the old line. If i understand this correctly the vector library provides the mechanism to implement vector modules to add new layer and copying existing categories into the new layer using the same vector map? My problem is that i want to successively add new layers (tables) to existing vector maps using existing categories. The problem is that the categories are not existing for a new layer because of the definition of a new layer. If there would be categories existing for that layer, the layer would already exist. I guess you must either use v.category option=transfer or have a bunch of tables but only one vector with one layer and disconnect/reconnect the tables as needed, only one table would then be connected to the vector at any given time. I have used that successfully for time series points some time ago, it's the fastest solution but needs some care in handling the tables. Probably not an option for the temporal database unless you want to introduce db.table.timestamp... This is currently not an option. But i guess i can modify v.category to support the transfer of categories to more than a single layer of a new map: v.category --o input=soils output=soils1 option=transfer layer=1,2,3,4,5,6,7,8,9,...,2000 This will copy the cats of vector map soils from layer 1 into the new layer 1 - 2000 of vector map soils2. Can you estimate how hard the implementation will be? Best regards Soeren btw: * v.timestamp with layer support is in svn * Vector layer timestamp support in the temporal GIS implementation is in my local svn copy and needs more testing - i need to create vector maps with multiple categorized layer. Markus M Additionally i need to timestamp the layer in the temporal database. It would be meaningful to timestamp layers at file level using v.timestamp too. An approach which i have in mind is to extent v.timestamp with a layer option, so that timetsamp text files can be created for each layer in the vector map directory. An application in the temporal GIS and for environmental modelling would be the observation of raster time series at specific vector point locations. The vector location do not change over time, but the attribute tables. Hence, for each observed time step a new timestamped layer and table will be added to the observation vector map and filled with raster values. i just started to investigate the new shiny world of multiple layer usage. I hope you enjoy it! I do. :) Best regards Soeren Markus M Best regards Soeren 2012/1/25 Martin Landa landa.mar...@gmail.com: Hi, db.copy from_table=soil to_table=soil_2 - makes copy of `soil` table v.db.addtable map=soil table=soil_2 layer=2 - it would overwrite `soil_2` table, but do nothing in this case, no feature have category defined in layer 2. Proposal: v.random --o -z seed=1 output=soil n=20 zmin=0 zmax=100 column=clay v.category input=soil out=soil2 option=transfer layer=1,2 --o db.copy from_table=soil to_table=soil_2 v.db.connect map=soil2 table=soil_2 layer=2 v.db.addcolumn map=soil2 layer=1 columns='sand_frac DOUBLE PRECISION' v.db.addcolumn map=soil2 layer=2 columns='sand_frac DOUBLE PRECISION' ... Martin -- Martin Landa landa.martin gmail.com * http://geo.fsv.cvut.cz/~landa ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev
Re: [GRASS-dev] Struggling using two layered vector maps with v.what.rast
Hi Sören, 2012/1/25 Sören Gebbert soerengebb...@googlemail.com: Hi Markus, 2012/1/25 Markus Metz markus.metz.gisw...@googlemail.com: 2012/1/25 Sören Gebbert soerengebb...@googlemail.com: 2012/1/25 Markus Metz markus.metz.gisw...@googlemail.com: Note that a GRASS layer is defined by the existence of at least one vector feature with at least one category value in that layer. That layer may or may not be attached to an attribute table. For examples, see v.in.ogr when importing several layers at once, the LiDAR filtering tools, or the vector output of r.stream.extract. I will have a look. Also the v.net.* modules, which make use of layers to distinguish between line and node costs with the help of layers. Why is a full vector copy needed in case of category transfer from one to another layer? Because category transfer takes place in the vector feature, i.e. modifies the coor file of the vector. v.category option=transfer does not add an attribute table (AFAIK). Maybe this function: off_t Vect_rewrite_line(struct Map_info *Map, int line, int type, const struct line_pnts *points, const struct line_cats *cats) can be used to add new layer using existing categories (from layer 1?) to an existing vector map? Adding a new layer always means adding new categories, also if they are identical to categories in a different layer. The difference between Vect_rewrite_line and the combination of Vect_delete_line, Vect_write_line is only that Vect_rewrite_line is supposed to check if the new line fits into the space used by the old line. If i understand this correctly the vector library provides the mechanism to implement vector modules to add new layer and copying existing categories into the new layer using the same vector map? Yes. But it is not recommended because the coor file will be filled up with dead lines (waste of disk space, slowing down reading). My problem is that i want to successively add new layers (tables) to existing vector maps using existing categories. The problem is that the categories are not existing for a new layer because of the definition of a new layer. If there would be categories existing for that layer, the layer would already exist. I guess you must either use v.category option=transfer or have a bunch of tables but only one vector with one layer and disconnect/reconnect the tables as needed, only one table would then be connected to the vector at any given time. I have used that successfully for time series points some time ago, it's the fastest solution but needs some care in handling the tables. Probably not an option for the temporal database unless you want to introduce db.table.timestamp... This is currently not an option. But i guess i can modify v.category to support the transfer of categories to more than a single layer of a new map: v.category --o input=soils output=soils1 option=transfer layer=1,2,3,4,5,6,7,8,9,...,2000 This will copy the cats of vector map soils from layer 1 into the new layer 1 - 2000 of vector map soils2. Can you estimate how hard the implementation will be? Not so hard ;) But with thousands of vector layers you could experience slowed down operations involving categories, slowed down exponentially with the number of layers. But maybe this only becomes an issue with hundreds of thousands of vector layers. btw: * v.timestamp with layer support is in svn * Vector layer timestamp support in the temporal GIS implementation is in my local svn copy and needs more testing - i need to create vector maps with multiple categorized layer. For the time being, you could run v.category option=transfer in a loop. Markus M Additionally i need to timestamp the layer in the temporal database. It would be meaningful to timestamp layers at file level using v.timestamp too. An approach which i have in mind is to extent v.timestamp with a layer option, so that timetsamp text files can be created for each layer in the vector map directory. An application in the temporal GIS and for environmental modelling would be the observation of raster time series at specific vector point locations. The vector location do not change over time, but the attribute tables. Hence, for each observed time step a new timestamped layer and table will be added to the observation vector map and filled with raster values. i just started to investigate the new shiny world of multiple layer usage. I hope you enjoy it! I do. :) Best regards Soeren Markus M Best regards Soeren 2012/1/25 Martin Landa landa.mar...@gmail.com: Hi, db.copy from_table=soil to_table=soil_2 - makes copy of `soil` table v.db.addtable map=soil table=soil_2 layer=2 - it would overwrite `soil_2` table, but do nothing in this case, no feature have category defined in layer 2. Proposal: v.random --o -z seed=1 output=soil n=20 zmin=0 zmax=100 column=clay v.category input=soil out=soil2
Re: [GRASS-dev] Struggling using two layered vector maps with v.what.rast
Hi, db.copy from_table=soil to_table=soil_2 - makes copy of `soil` table v.db.addtable map=soil table=soil_2 layer=2 - it would overwrite `soil_2` table, but do nothing in this case, no feature have category defined in layer 2. Proposal: v.random --o -z seed=1 output=soil n=20 zmin=0 zmax=100 column=clay v.category input=soil out=soil2 option=transfer layer=1,2 --o db.copy from_table=soil to_table=soil_2 v.db.connect map=soil2 table=soil_2 layer=2 v.db.addcolumn map=soil2 layer=1 columns='sand_frac DOUBLE PRECISION' v.db.addcolumn map=soil2 layer=2 columns='sand_frac DOUBLE PRECISION' ... Martin -- Martin Landa landa.martin gmail.com * http://geo.fsv.cvut.cz/~landa ___ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev
