Geology: Difference between revisions

Revision as of 01:12, 3 December 2008

See the IconSymbols wiki page

ps.map can take rotation angle from an attribute column for each site with the vpoints rotatecolumn instruction; for d.graph you can prepare a command file with a custom rotation for each point using v.out.ascii, v.db.select, or the v.out.ascii.db addon script. Note that GRASS uses the Cartesian convention for rotation angles, i.e. CCW from east. Convert from compass angles (CW from north) with:

    theta = 90 - degrees_true

You could possibly write a small db.execute script to populate a new column with this conversion by way of a SQL query. (and post it here :)

to make open symbols set the fill color to 'none'.
to make a double sided dip symbol draw the same symbol twice with 180 rotation the second time.

@@ Line 8: / Line 8: @@
 * <tt>geology/strike_line,box,triangle,circle</tt>:
 : [[Image:Symb-geo.png|350px]]
-* {{cmd|ps.map}} can take rotation angle from an attribute column for each site with the '''''vpoints''' rotatecolumn'' instruction; for {{cmd|d.graph}} you can prepare a command file with a custom rotation for each point using {{cmd|v.out.ascii}}, {{cmd|v.db.select}}, or the ''v.out.ascii.db'' addon script. Note that GRASS uses the Cartesian convention for rotation angles, i.e. CCW from east. Convert from compass angles with:
+* {{cmd|ps.map}} can take rotation angle from an attribute column for each site with the '''''vpoints''' rotatecolumn'' instruction; for {{cmd|d.graph}} you can prepare a command file with a custom rotation for each point using {{cmd|v.out.ascii}}, {{cmd|v.db.select}}, or the ''v.out.ascii.db'' addon script. Note that GRASS uses the Cartesian convention for rotation angles, i.e. CCW from east. Convert from compass angles (CW from north) with:
       theta = 90 - degrees_true
 : You could possibly write a small {{cmd|db.execute}} script to populate a new column with this conversion by way of a SQL query. (and post it here :)