On Sun, Mar 29, 2009 at 12:43 PM, James Maxwell <jbmaxw...@rubato-music.com> wrote: > Sorry for the long post, but I'm trying to wrap my head around NSData, > NSMutableData and matrices. > So I made an example to test my (mis)conception of how this all should work.
There are two ways to store two-dimensional data in a one-dimensional array. The standard way is row-major order, in which the rows of the data are contiguous. To compute the index for this method, you use index=row*columnCount+column. The other way is column-major order, which is just the opposite. The columns are contiguous. Here you compute the index as index=column*rowCount+row. You're computing the index as row*rowCount+column, which doesn't work. As a consequence, you're repeating indexes in your 1D array, which leads to funny results. Log your computed indexes as well as the values you find, and I believe the problem will be apparent. Mike _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
