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seen Nov 20 at 16:09

Nov
19
comment How to easily shift all features in a vector dataset?
Brilliant -- a simple one line CLI solution.
Aug
11
comment Writing numpy array to raster file
The "rotation is in twice" to account for the effect of a rotated bit of y on x and the rotated bit of x on y. See lists.osgeo.org/pipermail/gdal-dev/2011-July/029449.html which tries to explain the interrelationships between the "rotation" parameters.
Aug
4
comment gdal_grid failing to set nodata
They might be thinking of this as a default value to store in the array, while identifying that value as flag for nodata value is a separate function. That said, one would think that this might work: ######################## gdal_grid -co PROFILE=GDALGeoTIFF -co TIFFTAG_GDAL_NODATA=-9999 .... ############# but with gdal 11.1 it fails with "Warning 6: Driver GTiff does not support TIFFTAG_GDAL_NODATA creation option"
Aug
4
comment Bilinear interpolation of point data on a raster in Python?
ax,ay might have a problem if the grid is rotated at all. It might be better to transform your interpolate-to points into pixel or data coordinates. Also, if there is an off-by-one problem with them, then you might be going beyond the size of the band.
Aug
1
comment What is the inverse of QgsGeometry.asGeometryCollection() in qgis python?
combine looks like it would merge the parts, losing their individual identities. I don't want them merged into one, I want a new multipart geometry.
Aug
1
comment Negative UTM easting
110,000m/1852/60 = 0.998 degrees wide, which is too narrow. 6 degrees would be about 6*1852*60=666,720m wide.
Jul
30
comment What is the inverse of QgsGeometry.asGeometryCollection() in qgis python?
My motivation is the same specified distance redistributing-vertices use-case as in gis.stackexchange.com/q/107999/10229 but I'd like to know how to write things to deal with polygons, and potentially 2.5D polygons and polylines as well. (Ultimately, I need to redistribute the vertices unevenly, based on a raster or some function of a raster, but that's for later.)
Jul
30
comment What is the inverse of QgsGeometry.asGeometryCollection() in qgis python?
No, I do not want to replace the multipart with a set of component parts (like 'explode' ungroup, or multi-to-single). I want to unpack the multigeom into its component parts, apply a user-defined function (in the Q, myFunction() is an identity function as a , but a function like reverse_line(), densify(), simplify()) to the parts to make a set of new parts, then re-pack the new parts into a new, replacement multigeom to use as a replacement. In your answer, how do I append each g.exportToWkt() into a list, and convert the list back into a multipart geometry of the same type as geom?
Jul
25
comment What is the inverse of QgsGeometry.asGeometryCollection() in qgis python?
After I iterate, I then want to re-collect the list of paert into a type-conformant replacement for the original geometry. It appears that you can take apart all types of .isMultipart()==True geometries with .asGeometryCollection(), but you can't re-collect them with something like geom.replaceGeometry(geomColl).
Jul
24
comment What is the inverse of QgsGeometry.asGeometryCollection() in qgis python?
Can you point me toward MultiPolyline documentation? The list of objects returned by asGeometryCollection does not appear to be a list of Polylines.
Jul
24
comment What is the inverse of QgsGeometry.asGeometryCollection() in qgis python?
I'd like to process the lines within a selected multi-part polyline separately. My motivating example is in gis.stackexchange.com/a/108243/10229
Jul
24
comment Redistribute linestring vertices to specified distance
Thanks for the hint. I was able to redistribute the vertices to a specified distance in this question
Jul
22
comment How to create points in a specified distance along the line in QGIS?
Note that the "Sextante" toolbox is called "Processing" in QGIS 2.2.0+ and the the Densify geometries given a an interval" is under the ProcessingToolbox/QGISGeoalgorithms/VectorGeometryTools menu. Note that this denifies the geometry and doesn't remove vertices that are closer than the the chosen interval.
Jul
22
comment How to create points in a specified distance along the line in QGIS?
In QGIS 2.2.0, I see a "Profile tool", "qProf" and "VoGIS-ProfilTool", but not a "Profile from line" tool.
Jul
22
comment How to create points in a specified distance along the line in QGIS?
From looking at the junction, it looks like it keeps the pre-existing node points on the line, so it can't thin them to a resolution less than the vertices already on the line. With complicated, curvy lines as in the OP, these procedures may not have much of an effect.
Jul
22
comment How to run sextante algorithms outside of qgis python console?
Script Runner is updated here
Jul
22
comment How does one modify selected geometry with a function in qgis python console?
Thanks, edited.
Jul
22
comment How can I switch line direction in QGIS?
Did you use something like the PluginBuilder plugin mentioned on docs.qgis.org/testing/en/docs/pyqgis_developer_cookbook/… ?
Jul
15
comment How to densify a polyline according to a specific length?
Densify in Qgis appears to add a 1...n number of vertices to each line segment. In longer than 200m or shorter than 200m segments, the resolution would multiply, but not respect the specific length portion of the question as asked. Maybe gis.stackexchange.com/questions/27102/… is relevant, but it doesn't change the set of vertices along the lines.
May
23
comment How to manually edit point coordinates in QGIS?
Thanks. I found I had to close and reopen my project in order to un-grey out the tool. But after that, it works as advertised.