Still confusing: On Wed, May 31, 2017 at 03:36:33PM +1000, Karl Glazebrook wrote: > column-major all the way down, as image processing came before matrix ops and > i in A(i,j) is naturally the x-axis. but the x axis displays horizontally, as row, and when matrices are multiplied i is interpreted as column index, i.e., as index along row. > i.e. A[0,1] is followed by A[1,0] in memory You mean A[0,0] is followed by A[1,0] in memory, right? So memory is arranged as in fortran arrays (first index fastest), but the interpretation as row and column indices is different. Regards, Luis
> > > Karl > > > > > On 22 May 2017, at 6:32 am, Chris Marshall <[email protected]> wrote: > > > > Please ignore the following. Just mark me confused... > > > > --Chris > > > > On 5/21/2017 15:51, Chris Marshall wrote: > >> The row-major and col-major for PDL has always > >> confused me since, AFAICT the PDL dimensions and > >> slicing syntax actually are column major in > >> memory but we print them out in row-major. > >> > >> Maybe one of the original PDL developers could > >> give an explanation (of the history at least!). > >> > > > > > > ------------------------------------------------------------------------------ > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > _______________________________________________ > > pdl-general mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/pdl-general > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > pdl-general mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/pdl-general > -- o W. Luis Mochán, | tel:(52)(777)329-1734 /<(*) Instituto de Ciencias Físicas, UNAM | fax:(52)(777)317-5388 `>/ /\ Apdo. Postal 48-3, 62251 | (*)/\/ \ Cuernavaca, Morelos, México | [email protected] /\_/\__/ GPG: 791EB9EB, C949 3F81 6D9B 1191 9A16 C2DF 5F0A C52B 791E B9EB ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ pdl-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/pdl-general
