[GRASS-dev] v.proj transforming z co-ordinates

[Maciej Sieczka]

Paul Kelly wrote:

> That is very strange. Can you post the output from v.proj please to see
> if there are any clues?

Hi Paul!

Attached are 2 sample Grass locations.

zak_ll is latlong on WGS84 and contains an input 'test' 3D points
vector (created with 'v.random -z output=test n=10 zmin=0.0 zmax=3000.0').

zak_utm34 is UTM34 on WGS84 and contains 2 v.proj outputs:
'test_reproj_Z_no' and 'test_reproj_Z_yes', created by the following
commands, respectively:

$ v.proj input=test location=zak_ll mapset=test output=test_reproj_Z_no

$ v.proj -z input=test location=zak_ll mapset=test output=test_reproj_Z_yes

(You'll find a full v.proj output in the attached text file.)

For both output files I have uploaded their x,y,z coordinates into a
table, and I find there is *no difference* in either coordinate,
although the 1st vector was created using the v.proj with -z switch
while the 2nd without this switch. Looks like '-z' doesn't work?

Maciek
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GRASS 6.3.cvs (zak_utm34):~ > v.proj input=test location=zak_ll mapset=test output=test_reproj_Z_no

Input Projection Parameters: +proj=longlat +a=6378137 +rf=298.257223563 +no_defs +towgs84=0.000,0.000,0.000
Input Unit Factor: 1

Output Projection Parameters: +proj=utm +zone=34 +a=6378137 +rf=298.257223563 +no_defs +towgs84=0.000,0.000,0.000
Output Unit Factor: 1

Creating vector file...
Building topology ...
10 primitives registered
Building areas:  100%
0 areas built
0 isles built
Attaching islands:
Attaching centroids:  100%
Topology was built.
Number of nodes     :   10
Number of primitives:   10
Number of points    :   10
Number of lines     :   0
Number of boundaries:   0
Number of centroids :   0
Number of areas     :   0
Number of isles     :   0
GRASS 6.3.cvs (zak_utm34):~ > v.proj -z input=test location=zak_ll mapset=test output=test_reproj_Z_yes

Input Projection Parameters: +proj=longlat +a=6378137 +rf=298.257223563 +no_defs +towgs84=0.000,0.000,0.000
Input Unit Factor: 1

Output Projection Parameters: +proj=utm +zone=34 +a=6378137 +rf=298.257223563 +no_defs +towgs84=0.000,0.000,0.000
Output Unit Factor: 1

Creating vector file...
Building topology ...
10 primitives registered
Building areas:  100%
0 areas built
0 isles built
Attaching islands:
Attaching centroids:  100%
Topology was built.
Number of nodes     :   10
Number of primitives:   10
Number of points    :   10
Number of lines     :   0
Number of boundaries:   0
Number of centroids :   0
Number of areas     :   0
Number of isles     :   0
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