On 12 Aug 2014, at 00:41, Keary Suska <cocoa-...@esoteritech.com> wrote:
> > On Aug 11, 2014, at 2:52 PM, Dave <d...@looktowindward.com> wrote: > >> On 10 Aug 2014, at 16:16, Keary Suska <cocoa-...@esoteritech.com> wrote: >> >> >>> I don't think so, although I would expect a C lib somewhere to address it. >>> Anyway, isn't easier to just always abs(x)%y? >>> >> >> >>> abs(x)%y >> >> Doesn’t give the same result, it’s one off: >> >> myIndex: -5 myMod: 1 abs(x)%y: 2 >> myIndex: -4 myMod: 2 abs(x)%y: 1 >> myIndex: -3 myMod: 0 abs(x)%y: 0 >> myIndex: -2 myMod: 1 abs(x)%y: 2 >> myIndex: -1 myMod: 2 abs(x)%y: 1 >> myIndex: 0 myMod: 0 abs(x)%y: 0 >> myIndex: 1 myMod: 1 abs(x)%y: 1 >> myIndex: 2 myMod: 2 abs(x)%y: 2 >> myIndex: 3 myMod: 0 abs(x)%y: 0 >> myIndex: 4 myMod: 1 abs(x)%y: 1 >> >> Where: >> >> myIndex = input value. >> myMod = result of calling the mod function I added. >> abs(x)%y = abs(x)%y. > > Maybe my brain isn't working correctly but that doesn't make sense to me. > Could you show the output with both x and y shown? Now, you aren't dividing > by a negative integer, are you? I believe that is undefined… I’m not doing any division, the function for “myMod” is as I posted: Try it yourself: NSInteger myIndex; NSInteger myNewIndex; NSInteger myNewNewIndex; for (myIndex = -5;myIndex < 5;myIndex++) { myNewIndex = [self modulusWithDividend:myIndex andDivisor:3]; myNewNewIndex = abs(myIndex) % 3; NSLog(@"myIndex: %i myNewIndex: %i myNewNewIndex: %i",myIndex,myNewIndex,myNewNewIndex); } ————————————— If you think of the number as being used as an Index into an NSArray, you can see why a true mod function is better, e.g. -1 gets you the last element, -2 the second from last and so on. Cheers Dave _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com