[GRASS-user] Display point values

GRASS GRASS user
1

Rather than use raster DTM maps I decided to use depth measurement points
themselves.

The data look like this:
lon,lat,depth
7709581.42,697951.64,24
7705545.87,698624.07,16
7709732.27,699488.73,27
7712090.79,699428.24,62
7716863.99,701238.89,32
7701540.85,698790.50,31
7713676.33,699192.82,58
7705283.41,697549.00,31
7705037.10,698489.22,16

The command I'm using is:
d.vect map=lady_channel_sounding_points display=zcoor type=point zcolor=blue size=7

and the resulting map is attached.

Perhaps I should make the computational region smaller to make individual
values visible, but are the display and color values what they should be?
The values are displayed in red, not blue.

TIA,

Rich

(attachments)

channel-depths-png.png

2
(attachments)

depth_points.png

···

On 9/30/21 7:33 PM, Rich Shepard wrote:

Rather than use raster DTM maps I decided to use depth measurement points
themselves.

The data look like this:
lon,lat,depth
7709581.42,697951.64,24
7705545.87,698624.07,16
7709732.27,699488.73,27
7712090.79,699428.24,62
7716863.99,701238.89,32
7701540.85,698790.50,31
7713676.33,699192.82,58
7705283.41,697549.00,31
7705037.10,698489.22,16

The command I’m using is:
d.vect map=lady_channel_sounding_points display=zcoor type=point zcolor=blue size=7

and the resulting map is attached.

Here’s what I did. Notice that I added the “-z=3” option to v.in.ascii so that the new points vector is 3D. Then the “zcolor=” option to d.vect works.

Create new Location/Mapset based on the georeference tiff file

grass -c ~/Downloads/columbia_2010_e_dtm_35.tif --text ./columbia/PERMANENT

#Points text file
micha@RMS:tmp$ cat << EOF > depth_points.txt
lon,lat,depth
7709581.42,697951.64,24
7705545.87,698624.07,16
7709732.27,699488.73,27
7712090.79,699428.24,62
7716863.99,701238.89,32
7701540.85,698790.50,31
7713676.33,699192.82,58
7705283.41,697549.00,31
7705037.10,698489.22,16
EOF

Create GRASS vector from CSV file

Note the 'z=3" parameter, to creaate a 3D vector with Z coord

cat depth_points.txt | v.in.ascii input=- output=depth_points separator=comma z=3 skip=1 columns=“x DOUBLE, y DOUBLE, depth DOUBLE” --o
v.info depth_points | grep 3D
| Map is 3D: Yes
g.region -ap vect=depth_points

Display

d.mon wx1
d.vect depth_points zcolor=byr size=10 icon=basic/diamond

Result attached

Perhaps I should make the computational region smaller to make individual
values visible, but are the display and color values what they should be?
The values are displayed in red, not blue.

TIA,

Rich

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-- 
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918
3

On Thu, 30 Sep 2021, Micha Silver wrote:

Here's what I did. Notice that I added the "-z=3" option to v.in.ascii so
that the new points vector is 3D. Then the "zcolor=" option to d.vect
works.

Micha,

The command I used is:
v.in.ascii -zr in=~/projects/washington/project/data/bathymetry/coe/CL_34_WSHX_20210720_CS.xyz out=wash_transect format=point sep=comma columns='x double precision, y double precision, elev=int' x=1 y=2 z=3
--o

It has the -z option specified. It also has 'z=3' at the end to indicate the
elevation values are the third column in the file.

If I replace -zn with -z=3 GRASS tells me:
ERROR: v.in.ascii: Sorry, <=> is not a valid flag
ERROR: v.in.ascii: Sorry, <3> is not a valid flag

And GRASS still tells me:
ERROR: Unable to open input file
        </home/rshepard/projects/washington/project/data/bathymetry/coe/CL_34_WSHX_20210720_CS.xyz>:
        No such file or directory

It's quite frustrating as it had no problem finding CL_33_LDYX_20210712_CS.xyz
in the same directory just before I entered the command for importing CL_34_WSHX_20210720_CS.xyz.

Thanks,

Rich