Applying v.transform on set of vector layers using GRASS

Question

I am using GRASS 6.4.

I have 64 vector layers, all of them must be warped using the v.transform module; the pointsfile is the same for all vectors.

How can I apply the transformation recursively to all layers?

I don't want (for a bunch of reasons) to merge all layers into one and apply the transformation on the single file.

Answer 1

If you can do it for just one vector, then its easy to batch it.

For example, if this works for you:

v.transform input=in_vector_1 output=out_vector_1 xshift=11 yshift=12

then you can run this to one-shot them all:

for i in $(seq 1 74); do
    echo Transforming in_vector_$i
    v.transform input=in_vector_$i output=out_vector_$i xshift=11 yshift=12
    echo Done!
done

the trick is to name your data in a way you can iterate between them easily.

I assume you're using linux with bash.

Answer 2

I've managed to apply v.transform with an iteration like this:

for map in `g.mlist type=vect pattern=map_*`; do
        v.transform in=$map out=${map}_georef pointsfile=points_georef --o
done