hape geometries

[aiur]

I'm running a short Python script to offset and scale the geometry in a line shapefile. The geometry features move as planned, but the extent of the shapefile doesn't update as expected according the ogrinfo. The max xy are changed, but the min xy remain unchanged. Below I've pasted the Python script followed by the ogrinfo output. Do I need to add something to the Python script to get the extents refreshed?( I think this information is the shx file).

JavaBinding v1.10.0 has this problem too.
JavaBinding v1.10.0 has this problem too.

code:

#mine_to_utm.py
import ogr
#include the .shp extension
#sShpName = "section_lines_test_ln.shp"
sShpName = "test_utm_lnz.shp"
dXOffset = 1711586.62
dYOffset = 14712509.9
dScale = 0.3048
ogrdriver = ogr.GetDriverByName("ESRI Shapefile")
ogrSDS = ogrdriver.Open(sShpName, 1)
mLayer = ogrSDS.GetLayerByName(sShpName[:-4])
for i in range(mLayer.GetFeatureCount()):
   mFeature = mLayer.GetFeature(i)
   mGeom = mFeature.GetGeometryRef()
   #only process simple LINESTRING
   if (mGeom.GetGeometryCount() == 0):
     #create new wkt geometry
     sWkt = "LINESTRING ("
     for j in range(mGeom.GetPointCount()):
       dX = mGeom.GetX(j)
       dY = mGeom.GetY(j)
       dZ = mGeom.GetZ(j)
       dXNew = (dX + dXOffset) * dScale
       dYNew = (dY + dYOffset) * dScale
       sWkt += str(dXNew) + " " + str(dYNew) + " " + str(dZ) + ","
     sWkt = sWkt[:-1] + ")"
     newGeom = ogr.CreateGeometryFromWkt(sWkt)
     mFeature.SetGeometryDirectly(newGeom)
     mLayer.SetFeature(mFeature)
   else:
     print "Geometry not supported."
     print mGeom
     break
ogrSDS.Destroy()

S:\>ogrinfo -al test_utm_lnz.shp

INFO: Open of `test_utm_lnz.shp'
       using driver `ESRI Shapefile' successful.

Layer name: test_utm_lnz
Geometry: 3D Line String
Feature Count: 2
Extent: (25197.816780, 14676.458434) - (30479.027175, 30724.795652)
              ↑↑↑↑
Layer SRS WKT:
(unknown)
FID_: Integer (9.0)
OGRFeature(test_utm_lnz):0
   FID_ (Integer) = (null)
   LINESTRING (30409.466042881133 30667.436514034867 0,25433.42988651176 
30724.79
5651653782 0)

OGRFeature(test_utm_lnz):1
   FID_ (Integer) = (null)
   LINESTRING (30479.027175426483 14678.760769195855 
0,25197.816779945977 14676.4
58433972672 0)

S:\>mine_to_utm.py
S:\>ogrinfo -al test_utm_lnz.shp

INFO: Open of `test_utm_lnz.shp'
       using driver `ESRI Shapefile' successful.

Layer name: test_utm_lnz
Geometry: 3D Line String
Feature Count: 2
Extent: (25197.816780, 14676.458434) - (530981.609259, 4493737.935230)
              ↑↑↑↑
Layer SRS WKT:
(unknown)
FID_: Integer (9.0)
OGRFeature(test_utm_lnz):0
   FID_ (Integer) = (null)
   LINESTRING (530960.40702599997 4493720.4521700004 
0,529443.71120500006 4493737
.9352299999 0)

OGRFeature(test_utm_lnz):1
   FID_ (Integer) = (null)
   LINESTRING (530981.60925900005 4488847.1037999997 
0,529371.89633100003 4488846.4020499997 0)

[Jukka Rahkonen]

Hi,

I believe you should read the section "Spatial extent" in ​http://www.gdal.org/ogr/drv_shapefile.html and try to "invoke the SQL 'RECOMPUTE EXTENT ON <tablename>' via the datasource ExecuteSQL() method". I have no idea about how you can do it with your python code.

[aiur]

Replying to jratike80:

Hi,

I believe you should read the section "Spatial extent" in ​http://www.gdal.org/ogr/drv_shapefile.html and try to "invoke the SQL 'RECOMPUTE EXTENT ON <tablename>' via the datasource ExecuteSQL() method". I have no idea about how you can do it with your python code.

Hi, Thank you so much. but how can i find tablename in shapefile ?

[aiur]

Replying to jratike80:

Hi,

I believe you should read the section "Spatial extent" in ​http://www.gdal.org/ogr/drv_shapefile.html and try to "invoke the SQL 'RECOMPUTE EXTENT ON <tablename>' via the datasource ExecuteSQL() method". I have no idea about how you can do it with your python code.

I got it, Thank you so so so much.