Geology: Difference between revisions

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(+cat doc)
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* <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]]
* <tt>geology/half_arrow</tt>:
: [[Image:Half_arrow_x2.png]]
: (two displayed, one of which has been rotated 180 degrees)
* {{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:
* {{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
     theta = 90 - degrees_true

Revision as of 08:49, 18 September 2011

Modules of interest

see also r3.* commands
  • nviz: Native 3D visualization and animation suite (interactive cutting planes through stacked 3D grid surfaces, etc.)
  • v.out.vtk, r.out.vtk, and r3.out.vtk: Export to VTK format for ParaView or other 3D visualization software
  • ...


Cartography

Examples

Strike-and-dip symbols

See the IconSymbols wiki page

  • geology/strike_line,box,triangle,circle:
  • geology/half_arrow:
(two displayed, one of which has been rotated 180 degrees)
  • 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.

Fill patterns

  • AreaFillPatterns: ps.map allows custom fill patterns based on simple PostScript-like rules files. A number of patterns are provided. It is reasonably simple to create new ones- just copy an existing one to a new file and edit the drawing coordinates in a text editor. (new contributions welcome)

Dashed lines

In ps.map use the vlines style instruction to set the line style. The linecap instruction can further refine the draw mode.

Links

  • ...