[GRASSLIST:7152] v.in.ascii and 6.* tables

GRASS GRASS user
1

Hi,

I want to import an ASCII x,y,value into a Grass 6.* vector map and use r.surf.idw to interpolate a surface. I can’t seem to get the syntax right.

A line of the ASCII file:

89.1 23.5 1202.1232

that represent x y value.

I use:

cat file1.tab | v.in.ascii out=map1 x=1 y=2 cat=3 fs=\ columns=‘x double, y double, cat double’

v.in.ascii reports 12838 point imported, and I can display them ok.

I then try:

v.surf.idw input=map1 output=map1r col=cat

v.surf.idw complains: ERROR: Cannot open old vector map1@jwortel on level 2.

I suppose the col option should point to a field in the attribute table of map map1, but I don’t see any associated mpa1.dbf file.

any help is greatly appreciated.

Jeroen.

2

I want to import an ASCII x,y,value into a Grass 6.* vector map and
use r.surf.idw to interpolate a surface. I can't seem to get the
syntax right. A line of the ASCII file:

89.1 23.5 1202.1232
that represent x y value.
I use:
cat file1.tab | v.in.ascii out=map1 x=1 y=2 cat=3 fs=\ columns='x
double, y double, cat double'

fs=\ ?
category must be an integer.

v.in.ascii reports 12838 point imported, and I can display them ok.

Ok. Try a query with d.what.vect to be sure.

I then try:
v.surf.idw input=map1 output=map1r col=cat
v.surf.idw complains: ERROR: Cannot open old vector map1@jwortel on
level 2. I suppose the col option should point to a field in the
attribute table of map map1, but I don't see any associated mpa1.dbf
file.

maybe "old vector" is an important clue?

What does v.info say?

Hamish

3

Hi Hamish,

I found out the correct syntax after some extra experimenting.

I was not sure how to cope with the category value, but saw that I need auto-assignment of actegory number with cat=0. I then specify the value that I wan't to interpolate as a double.

in the file:

         89.1 23.5 1202.1232

syntax:
         cat file1.tab | v.in.ascii out=map1 x=1 y=2 cat=0 fs=space columns='x double, y double, value double'

I then use the attribute 'value' to interpolate.

I was somewhat confused that 'x' and 'y' need to be specified again in the columns option, but 'cat' not, although it is still a field in the resulting dbf. But then it isn't in the inputfile, isn't it.

You were right that fs=\ is wrong, it should of course be fs=space. I was confused with scripting syntaxes.

Thanks for your help,

-Jeroen.

fs=\ ?
category must be an integer.

> v.in.ascii reports 12838 point imported, and I can display them ok.

Ok. Try a query with d.what.vect to be sure.

> I then try:
> v.surf.idw input=map1 output=map1r col=cat
> v.surf.idw complains: ERROR: Cannot open old vector map1@jwortel on
> level 2. I suppose the col option should point to a field in the
> attribute table of map map1, but I don't see any associated mpa1.dbf
> file.

maybe "old vector" is an important clue?

What does v.info say?

Hamish

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