On Sun, Mar 23, 2008 at 04:15:28AM -0500, Allen Hall wrote: > Here's what I'm trying to do: > 1) mark the surface based on surface-gradient (this selects all surfaces > with the same slope within a certain tolerance)
This is directly possible with Statistics -> Facet analysis. If you mean gradient as a vector, i.e. including its direction -- which I gather you do from your further comments. Selecting just by the absolute gradient value is not easily possible. > 2) determine their total area (projected) > 3) determine their total real area (by muliplying by the cos(angle)) I suppose you mean by dividing by cos(angle), but yes, these are exactly what grain statistics calculate as the projected and surface area. Or rather exactly in the case of projected (flat) area; the real area is estimated from a surface triangulation, as described in the user guide, but if the surface is of more or less constant slope the result should be the same. And they can be exported to a file as a table with values for individual grains using Grains -> Distributions (with Raw output type). > So, when you say "projected" area- do you mean the area of the > highlighted grain projected onto the view-plane (flat plane in z)? Yes, precisely. Yeti ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Gwyddion-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/gwyddion-users
