On Mon, Jan 11, 2010 at 2:02 PM, Carnell, James E <jecarn...@saintfrancis.com> wrote:
>> I want to subtract the Red Value in an array cell from a neighboring >> Red Value cell. >> >> >>> pictArray[39][4] #pixel at 39 4 >> array([150, 140, 120], dtype=unint8) >> >> >>> pictArray[39][5] #pixel at 39 5 >> array([160, 150, 120], dtype=unint8) >> >> >>> pictArray[39][4][0] #red pixel >> 150 >> >> >>> pictArray[39][5[0] #neighboring red pixel >> 160 >> >> >>> pictArray[39][4][0] - pictArray[39][5][0] >> 246 # <--------------- ??? vs -10 >> >> How do I get the number -10? Does this have to do with the dtype? > - pictArray[39][4][0] - pictArray[39][5][0] = 246 is where I am > getting stuck I guess the subtraction is happening on unsigned values, which can't represent -10. Try int(pictArray[39][4][0]) - int(pictArray[39][5][0]) Kent _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
