Aug 31 2011

Intersection of line segments

Tag: softwareadmin @ 10:33 am

A post by Loren Shure of Mathworks, reminded me of a function, PolylineIntersectSegment.m, that I wrote to compute the intersection of a polyline with a line segment. This function nicely combines the topics of my last two posts, use of complex variables and lines, so I will discuss it in more detail. The use of complex variables simplifies the code and makes it easier to understand and modify.

Aug 17 2011

A Line object–basic formulas

admin @ 4:16 pm

Computational geometry is an interesting and important topic for imaging in general and x-ray imaging in particular. In this post, I describe the basic formulas for perhaps the most fundamental geometric object—a straight line in three dimensions. The object can also be used in 2D to represent a line in an image.

Aug 09 2011

The uses of complex variables in Matlab

admin @ 9:49 am

One of my Matlab programming styles, some would say quirks, is wide use of complex variables. I not only use them in the standard mathematical places but I use them to represent two dimensional spatial vectors and to represent two dimensional quantities in general.

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