# Synopsis

int mth_CheckDirColin(int ndim, double tol, double *p1, double *p2, double *p3)

# Purpose

Determine if three points are directionally colinear.

# Description

The three specified points will be checked for colinearity in the direction that they are specified (i.e. are only colinear if the vector from p1 to p2 is the same direction as the vector from p2 to p3 and the 3 points are colinear). The tol tolerance value is an angular tolerance measure.

# Input

## ndim

Number of dimensions in vectors (must be 3)

## tol

Tolerance of comparison

## p1

First point

## p2

Second point

## p3

Third point

# Return

          0 - Points are not colinear
          1 - Points are colinear
          .fi