Hi, I have added a new C module in the addons svn which will draw wind barbs, straw plots, and arrow plots from a raster array or sparse vector point data. It can use either direction + magnitude, or u + v components as the input, and can produce a legend key.
Some of this functionality is already covered by d.rast.arrow and d.vect, but I thought I'd bring it together into a dedicated tool and add some commonly needed options. It's still a work in progress, and there are still a few things on the todo list, but I think it's ready to get some testing now. Once the bugs are out and the design & feature set have been finalized I'd port it to grass7 and hope to add it to the main distribution + GUI. (One weird thing I notice is that in the tcl/tk GUI the legend_at= option appears as a tick box not a text entry field. ?) http://grass.osgeo.org/wiki/GRASS_AddOns#d.barb http://trac.osgeo.org/grass/browser/grass-addons/display/d.barb screenshot: (style=arrow) http://bambi.otago.ac.nz/hamish/grass/screenshots/narr-a_221_20100629_1800_000_10m_winds.png maybe g.extension works to install it if you compiled grass yourself? (I haven't tried installing it that way yet) comments, wishes, & criticisms welcome. usage follows, see the help page for more explanation & examples. Hamish -------------------------------------- GRASS65> d.barb --help Description: Draws flow barbs. Keywords: Usage: d.barb [-r] [direction=name] [magnitude=name] [u=name] [v=name] [input=name] [layer=value] [style=string] [color=name] [skip=value] [scale=value] [peak=value] [aspect_type=string] [legend_at=x,y[,x,y,...]] [legend_velo=value[,value,...]] [legend_fontsize=value] [--verbose] [--quiet] Flags: -r Rotate direction 180 degrees Useful for switching between atmospheric and oceanographic conventions --v Verbose module output --q Quiet module output Parameters: direction Raster map (or attribute column) containing velocity direction magnitude Raster map (or attribute column) containing velocity magnitude u Raster map (or attribute column) containing u-component of velocity v Raster map (or attribute column) containing v-component of velocity input Name of input vector map layer Layer number A single vector map can be connected to multiple database tables. This number determines which table to use. default: 1 style Style options: arrow,barb,straw default: arrow color Color Either a standard color name or R:G:B triplet default: black skip Draw arrow every Nth grid cell default: 10 scale Scale factor for arrow rendering default: 1.0 peak Maximum value for scaling (overrides map's maximum) aspect_type Direction map aspect type options: cartesian,compass default: cartesian legend_at Screen percentage for legend barb ([0,0] is bottom-left) Draws a single barb and exits options: 0-100 default: 10.0,10.0 legend_velo Velocity for legend key arrow legend_fontsize Font size used in legend default: 14 _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
