I apologise in advance for such a silly question. Normally, I start to write to the list and work the answer out before sending the mail. Not this time. I'm trying to work out which triangles contain the cartesian origin (0, 0) and have the following:
t = [-340, 495, -153, -910, 835, -947] print (0 - t[0])*(t[3] - t[1]) - (0 - t[1])*(t[2] - t[0]) print (0 - t[4])*(t[3] - t[5]) - (0 - t[5])*(t[2] - t[4]) print (0 - t[4])*(t[1] - t[5]) - (0 - t[5])*(t[0] - t[4]) where t is coordinates of triangle a,b,c and the maths is cross-product of vectors - if all are negative then it contains the origin. Unfortunately, when I run the programme, I get: co...@colin-laptop:~/lib/python/euler$ python p102origin.py -385135 904741 -91345 The second number should be negative ( I WANT it to be negative). For example: print (0 - t[4])*(t[3] - t[5]) , (0 - t[5])*(t[2] - t[4]) gives : -30895 -935636 And in the python shell: >>> -30895 -935636 -966531 But: print (0 - t[4])*(t[3] - t[5]) < (0 - t[5])*(t[2] - t[4]) gives : False >>> a = "No Error Message" >>> b = "Correct Answer" >>> a == b False Please forgive an old man a stupid question
_______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
