# IntersectPoint: Find where point opposite segment intersects segment. In pathmapping: Compute Deviation and Correspondence Between Spatial Paths

## Description

Find where point opposite segment intersects segment. It gives a proportion of AB that the orthogonal line passing through C meets. If outside (0,1) it does not pass through AB

## Usage

 `1` ```IntersectPoint(A, B, C) ```

## Arguments

 `A` `(x,y)` point on one end of line segment `B` `(x,y)` point on other end of line segment `C` `(x,y)` point to compare to line segment

## Value

returns a value which is the proportion of the length of `AB` where `AC` proects onto the line defined by AB. If the return value is between 0 and 1, the point is opposite the line segment. If negative, it falls on the `A` side of `AB`; if greater than 1, it falls to the `B` side of `AB`.

## Author(s)

Shane T. Mueller and Brandon Perelman

## References

See Mueller et al., (2016). https://sites.google.com/a/mtu.edu/mapping/

`LineMagnitude`,`ClosestPoint`,`DistancePointSegment`