[GRASS-dev] getting cat value of node

GRASS GRASS developer
1

Hi,

I'm trying to figure out a way to find the cat value of a node. Using
Vect_get_line_nodes() returns the ids of the initial and end node of a
line. However, these ids are not the cat values of those nodes. I've
looked into Vect_cat_get() but this function returns the first
category value from the layer. Any ideas?

Thanks,

Jaime

2

Hi,

2008/4/30 Jaime Carrera <jaime.carrerah@gmail.com>:

I'm trying to figure out a way to find the cat value of a node. Using
Vect_get_line_nodes() returns the ids of the initial and end node of a
line. However, these ids are not the cat values of those nodes. I've
looked into Vect_cat_get() but this function returns the first
category value from the layer. Any ideas?

AFAIK category value can be assigned only to the simple features like
points, lines, boundaries, centroids, faces or kernels. Assigning
category value to node (vertex) is not currently supported. Workaround
can be to create additional vector point layer derived from nodes
(v.to.points -n).

Martin

--
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa *