Hi David, while I suffer from the same type of dyslexia (even after all these years I still have trouble getting the indices right and frequently have to sketch what the layout of the data is and what it should be, using Fortran, C and a couple of other languages), I must point out that plsurf3d uses the _C_ ordering. You can see this for yourself in bindings/f(77|95)/sc3d.c which contains the Fortran-callable wrapper for that function. There the array z is transposed to fill the temporary array temp.
(I hope I do remember this correctly: the Fortran ordering is called column-major and C ordering is called row-major.) Regards, Arjen On 2010-01-06 09:11, David MacMahon wrote: > As I said in an earlier message, I'm working on Ruby bindings to > PLplot that are analogous to the Ruby bindings to PGPLOT. Like the > PGPLOT Ruby bindings, I've chosen to use/support the Ruby "NArray" > extension (http://narray.rubyforge.org/) for data arrays. I just > implemented the plsurf3d function and it works great, but... > > NArray stores 2D data (like the z data for plsurf3d) in a nx*ny > element 1D array in (I think) FORTRAN ordering (I think it's known as > "column major" ordering, but I always seem to suffer from row/column > dyslexia when it comes to remembering which is which). So to get the > plots in example 8 to look right, I have to index the NArray z data > as z[j,i] rather than z[i,j] (where i is the index in the "x > dimension" and j is the index in the "y dimension"). I also have to > dimension the z array "backwards" (so I can use the indexes > "backwards"). > > To interface NArray's 2D data with plsurf3d, I have to allocate and > populate an array of nx pointers to arrays of ny values. Since the y > values have to be contiguous in memory for plsurf3d, using the > "backwards" indexing scheme (perhaps "pre-transposed" is a more apt > term?) with NArray's 2D data saves a lot of memory copying. > > While this is a little odd feeling, I don't think this will be a > "problem" per se, so the following is a low priority feature > request: It would be nice if plsurf3d (and presumably other 3D > functions that I haven't gotten to yet) supported an option (e.g. > "TRANSPOSED_Z") that would indicate z is being given as an array of > ny pointers to arrays of nx values rather than the other way around. > > Is there some existing way to accomplish the same thing? How does > the FORTRAN interface to plsurf3d work? > > Thanks, > Dave > > > ------------------------------------------------------------------------------ > This SF.Net email is sponsored by the Verizon Developer Community > Take advantage of Verizon's best-in-class app development support > A streamlined, 14 day to market process makes app distribution fast and easy > Join now and get one step closer to millions of Verizon customers > http://p.sf.net/sfu/verizon-dev2dev > _______________________________________________ > Plplot-devel mailing list > Plplot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/plplot-devel > ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
