Geology: Difference between revisions

From GRASS-Wiki
Jump to navigation Jump to search
m (→‎Strike-and-dip symbols: man page link)
Line 8: Line 8:
* <tt>geology/strike_line,box,triangle,circle</tt>:
* <tt>geology/strike_line,box,triangle,circle</tt>:
: [[Image:Symb-geo.png|350px]]
: [[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 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 with:
     theta = 90 - degrees_true
     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 :)
: 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 :)

Revision as of 01:11, 3 December 2008

Examples

Strike-and-dip symbols

See the IconSymbols wiki page

  • geology/strike_line,box,triangle,circle:
  • 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 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.

Modules of interest

Links

  • ...