On Fri, Apr 9, 2010 at 8:04 AM, Peyman Askari <peter_peyman_...@yahoo.ca> wrote: > > Hello > > This is partly Python related, although it might end up being more math > related. > > I am using PyGTK (GUI builder for Python) and I need to find the intersection > point for two lines. It is easy to do, even if you only have the four points > describing line segments > (http://www.maths.abdn.ac.uk/~igc/tch/eg1006/notes/node23.html). However, it > requires that you solve for two equations. How can I do this in Python, > either solve equations, or calculating intersection points some other way?
Just solve the equations ahead of time by using generic ones. Given: y = mx + b y = nx + c We set them equal and solve for x: mx + b = nx + c mx - nx = c - b (m-n)x = c - b x = (c - b) / (m-n) So we now have a formula for x. y can then be calculated using the numerical value of x and one of the original formulas for y. If your equations are not in slope-intercept form, the same approach works, just use different, appropriate initial equations. Alternately, you could use a linear algebra library to solve the system of equations; NumPy sounds like it has at least part of one. But this is probably overkill for such a simple problem. Cheers, Chris -- Zero is my hero! Squi FTW. http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
