[Tutor] inside

[Shi Mu]

there is no error message but in the console
I just see Simple pointInPoly() test...


On 11/6/05, Liam Clarke <ml.cyresse at gmail.com> wrote:
> Shi,
>
> I've just seen 3 queries from you all along the lines of -
>
> why the following code does not work?
>
> <code>
>
> If English is not your first language, I can understand you're not
> going to write us a novel.
> However, you'll get a better response if you copy and paste the error
> message (the traceback) that you're getting in the console.
>
> Do you know how to copy and paste from the console?
>
> A lot of us aren't anywhere we can run your code; if we did, it may
> work, the error may not be an unhandled exception, just unexpected
> behaviour, and we have no idea what behaviour you're expecting.
>
> So please, in future give us this basic information -
>
> If there's an error message - copy and paste the error message
> If there is no error message - tell us what you expected to happen,
> and what happened instead.
>
> Regards,
>
> Liam Clarke
> On 11/7/05, Shi Mu <samrobertsmith at gmail.com> wrote:
> > why the following code does not work?
> >
> > # determine if a point is inside a given polygon or not
> > # Polygon is a list of (x,y) pairs.
> >
> > def point_inside_polygon(x,y,poly):
> >
> >     n = len(poly)
> >     inside =False
> >
> >     p1x,p1y = poly[0]
> >     for i in range(n+1):
> >         p2x,p2y = poly[i % n]
> >         if y > min(p1y,p2y):
> >             if y <= max(p1y,p2y):
> >                 if x <= max(p1x,p2x):
> >                     if p1y != p2y:
> >                         xinters = (y-p1y)*(p2x-p1x)/(p2y-p1y)+p1x
> >                     if p1x == p2x or x <= xinters:
> >                         inside = not inside
> >         p1x,p1y = p2x,p2y
> >
> >     return inside
> >
> > if __name__ == '__main__':
> >        print 'Simple pointInPoly() test...'
> >
> >        poly = [(-1,-1), (6,-1), (5,6), (0,5)]
> >        point_inside_polygon(3,10,poly)
> > _______________________________________________
> > Tutor maillist  -  Tutor at python.org
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> >
>