Greetings! I'm new to Qgis and GRASS, and not particularly experencienced in GIS as a whole, so apologies if what I'm asking betrays some basic lack of understanding on how things work.
I did some searches in how to "place" a vector layer that was based on a grid with a specific 0,0 datum and simple cartesian coordinates into another layer that represents the world and after some time I settled on using an affine transformation, which seems to be the only - or at least better - way[1]. This led me to v.transform.pointsinfile[2]. This command was failing (the last error I got in the log pane was "Could not determine input map's feature type(s)") so I did some further experiemting and noticed this: 1) If I create a vector layer (from a CSV containing a list of artefacts with x/y coordinates, via add delimited text layer) inside Qgis (which works and is perfectly visible around WGS84 0,0), and then apply v.transform.pointsinfile (with a point file I made), the command fails 2) If I use GRASS directly to import the CSV (using v.in.ascii), and then use Qgis GRASS integration to add the GRASS layer in Qgis, then performing v.transformation.pointsinfile works without any problem. Is this a behaviour that is to be somewhat expected? Perhaps it points towards some problems with my GRASS configuration (other GRASS commands work in Qgis though)? I'm attaching the processing.log just in case it is useful, as well as the pointfile and original CSV. All should work in GRASS (and move three points somewhere in the South Atlantic to the surroundings of Lisbon). Additional information: Qgis 2.2.0, GRASS 6.4.3, x86_64 in Ubuntu GNU/Linux (saucy). Any help welcome, of course. Best regards, Frederico [1] I think that a custom CRS, with 0,0 tied to a lat/long and with the angle specificed could also work for a small grid which is assumed to be flat, but I could be wrong. The plan is to project an archaeological grid (which uses relative coordinates [2] qgsaffine requires information that I apparently get from v.transform, so I didn't explored it further since I do not have the information to fill the dialog.
# Linear transformation from XY to UTM coordinates: # 4 maps corners defined # UL NW # UR NE # LR SW # LL SE # 38,714231, -9,323088 #0 580 -9.32169 38.67235 0 15 -9.323206 38.714416 5 15 -9.32300 38.71444 5 0 -9.322967 38.714232 0 0 -9.323152 38.714208 #-584 585 598000 4920770 # 580 585 598020 4920770 # 580 -600 598020 4920750 #-584 -600 598000 4920750
processing.log
Description: application/force-download
ID,Quad,UE,Tipo,Desc,x,y,z 34,B7,2,CER,Bordo,1.77000,1.70000,53.20000 194,B6,7,CRV,Semente,2.20000,1.20000,51.35000 195,B6,7,CRV,Carvão,1.20000,0.30000,51.35000
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