DESCRIPTION

v.net.alloc allocates subnets for nearest centres (direction from centre). Centre node must be opened (costs >= 0). Costs of centre node are used in calculation. Supported are cost assignments for both arcs and nodes, and also different in both directions of a vector line. For areas cost will be calculated along boundary lines.

NOTES

Center nodes have to be assigned to vector nodes using v.digit or added from other map(s). Nodes and arcs can be closed using cost = -1.

EXAMPLES

Example 1: Calculating subnets for 3 centre nodes using distances 
#Spearfish

# centre nodes:
echo "591235.5|4926306.62|1
596591.8|4917042.5|2
602722.9|4923544.2|3" | v.in.ascii out=centrenodes

g.copy vect=roads,myroads

#connect points to network
v.net myroads points=centrenodes out=myroads_net op=connect thresh=200

# view map
g.region vect=myroads_net
d.mon x0
d.vect myroads_net
d.vect myroads_net col=red icon=basic/triangle fcol=green size=12 layer=2

# allocate, specifying range of center cats (easier to catch all):
v.net.alloc myroads_net out=myroads_net_alloc ccats=1-100000 nlayer=2

# report categories
v.category myroads_net_alloc option=report

# the result has to be selected by category number of the relevant node:
d.vect myroads_net_alloc cat=1 col=red
d.vect myroads_net_alloc cat=2 col=green
d.vect myroads_net_alloc cat=3 col=yellow
d.vect myroads_net col=red icon=basic/triangle fcol=green size=12 layer=2

v.net.alloc example

Example 2: Calculating subnets for 7 centre nodes using cost assigned to vector length 

v.net.alloc in=vectmap out=vectmap.alloc ccats=1-7

Example 3: Calculating subnets for 7 centre nodes using cost assignments in both directions

v.net.alloc in=vectmap afcol=INDEX abcol=INDEXBACK out=vectmap.alloc ccats=1-7

SEE ALSO

d.path, v.net, v.net.iso, v.net.path, v.net.steiner, v.net.salesman

AUTHOR

Radim Blazek, ITC-Irst, Trento, Italy

Last changed: $Date$