[GRASS-user] using v.to.rast

[Janet Choate]

Hi users,
i've read the help and other posts regarding v.to.rast, but i'm still not
piecing it all together and would appreciate some help.
i have a vector map of roads that i want to convert to a raster, so it is
lines.  v.support - fine, but i can not figure out what i need to do with
v.digit (and if v.digit is necessary), don't know how to use.  after
running v.support, if i just run v.to.rast as:

v.to.rast input=roads output=roads
ERROR: Column parameter missing (or use value parameter)

but if i run as:
v.to.rast input=roads output=roads5 use=attr column=ROADNR
(or column=CODE, etc..)

then i get a raster.  values of the raster differ based on what column i
choose.  so my question is, how do i choose the column, and how do i know
what to set use= to (*attr,cat,val,z,dir)*
*
*
running db.describe on the road vector, i get the following info:
db.describe -c table=roads
ncols: 14
nrows: 383
Column 1: cat:INTEGER:11
Column 2: UserId:INTEGER:11
Column 3: FNODE_:INTEGER:11
Column 4: TNODE_:INTEGER:11
Column 5: LPOLY_:INTEGER:11
Column 6: RPOLY_:INTEGER:11
Column 7: LENGTH:DOUBLE PRECISION:20
Column 8: GI00701_:INTEGER:11
Column 9: GI00701_ID:INTEGER:11
Column 10: YEAR:INTEGER:11
Column 11: ROADDEC:INTEGER:11
Column 12: CODE:INTEGER:11
Column 13: STAT:CHARACTER:1
Column 14: ROADNR:INTEGER:11

if anyone can please advise the process of turning a vector into a raster,
i.e. what commands are necessary first and how to apply them, i would
really appreciate it.
thank you,
Janet
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