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    This is the community forum for my apps Pythonista and Editorial.

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    Equally spaced circle in UI

    Pythonista
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    • mikael
      mikael @AZOM last edited by

      @AZOM, sounds like a school exercise. Wouldn’t it be more useful for your friend to spend the time on cracking it?

      AZOM 2 Replies Last reply Reply Quote 0
      • AZOM
        AZOM @mikael last edited by AZOM

        @mikael

        No, we are in high school, and this is not a homework or something like that, he just like maths and wants help to “verify” his answer to a question he gets somewhere on the web.

        1 Reply Last reply Reply Quote 0
        • AZOM
          AZOM @mikael last edited by AZOM

          @mikael

          The only thing I am doing wrong is with rounding up numbers (I think it is my only problem) beau a se if 2 values that I compare are like at 0,000001 appart, they are not equal. Also, I am using cos and sin to try to find the three points. And my friend doesn’t program btw.

          mikael 2 Replies Last reply Reply Quote 0
          • mikael
            mikael @AZOM last edited by

            @AZOM, try

            0.1 + 0.2 == 0.3
            

            If you are not satisfied with the result, you might try to use the Decimal class, where you can also

            getcontext().prec == 6
            
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            • mikael
              mikael @AZOM last edited by

              @AZOM, meanwhile, for your problem, I would use ui.Path with the three points, then hit_test with the given point. I do not know whether this would be any more accurate than the method you are using, though.

              AZOM 1 Reply Last reply Reply Quote 1
              • AZOM
                AZOM @mikael last edited by

                @mikael

                Right, now, I don’t have my program, but I’m going to send it at ~5h pm.

                mikael 1 Reply Last reply Reply Quote 0
                • mikael
                  mikael @AZOM last edited by

                  @AZOM, going to get my beauty sleep now, but here’s what I meant by the hit test:

                  import random
                  import ui
                  import vector
                  
                  random_angle = lambda: random.random() * 360
                  
                  p = ui.Path()
                  point = vector.Vector(0, 1)
                  
                  point.degrees = random_angle()
                  p.move_to(*point)
                  print(point)
                  for _ in range(2):
                      point.degrees = random_angle()
                      p.line_to(*point)
                      print(point)
                  p.close()
                      
                  print('IN' if p.hit_test(0.5,0) else 'OUT') 
                  
                  1 Reply Last reply Reply Quote 1
                  • JonB
                    JonB last edited by

                    So, are you trying to input 3 points (not all colinear) and find the circle (radius and x,y). Then want to determine if a fourth point is on the edge of the circle?

                    A simple method is to just subtract the center, then compute the length, then compare to the circle radius. But, as you found, you want to use abs(point_to_center_dist-circle_radius)< threshold, where you'll have to decide what is an acceptable threshold.

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