Pedro Roma wrote: > I'm reading r.colors manual webpage ( > http://grass.itc.it/grass64/manuals/html64_user/r.colors.html) and I have a > few questions related with defining new color tables. > 1- At color (in Parameters) one of the options is rules. But if i select > rules and insert a path to a rules file I get this error: > *ERROR: "color", "rules", and "raster" options are mutually exclusive* > > * > * > > Was this suppose to happen?
Yes. If you specify a file for "rules", the "color" option should be blank. [color=rules exists for compatibility with previous versions, and only works from the command-line, not the GUI.] > 2- About color tables with absolute values (e.g. NDVI) if a NDVI pixel has > value between 2 defined values, which color does it get? It's interpolated. This is true whether the rules uses absolute values or percentages (or a mix of both). > 3- About aspectcolr*.* To each category a color is assigned (e.g. white, > yellow bla bla bla). Is there a list of possible colors to assign? The list of named colours is: white black red green blue yellow magenta cyan aqua grey gray orange brown purple violet indigo You can mix named colours and r:g:b notation freely. > 4- Regarding assigning a rules.info to a map (as it's demonstrated in the > same manual page). There are two ways. How come r.colors can use, as an > input, rules.info if it's stated before the r.colors statement. > cat rules.file | r.colors map=threecats color=rules color=rules reads rules from stdin, which in the above example is the contents of the rules.file via "cat". The following commands will all achieve the same result: cat rules.file | r.colors map=threecats rules=- r.colors map=threecats color=rules < rules.file r.colors map=threecats rules=- < rules.file r.colors map=threecats rules=rules.file For reading from a file, the last one is preferable (and is the only one which will work from the GUI). Beyond that, using rules=- is preferred to color=rules (apart from anything else, rules=- works in 7.0 while color=rules doesn't; color=rules is only kept in 6.4 for backwards compatibility). The use of "cat file | ..." rather than "... < file" can be easier to read if you're creating a long pipeline in a script, as it places the source file at the far left of the command. The following both have the same effect: cat infile | cmd1 | cmd2 | ... | cmdN > outfile cmd1 < infile | cmd2 | ... | cmdN > outfile but the former is probbably clearer. > 5- One last question :) I tried to display the color table associated with a > raster map layer (d.colortable) but I get the following message: > Command 'd.colortable' not yet implemented Odd; you can try d.legend instead, or use r.mapcalc to create a test map to which you can assign the colour table. -- Glynn Clements <gl...@gclements.plus.com> _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user