ISNEAR determines if two numbers are near each other as defined by prox
SYNOPSIS
function r = isnear(a,b,prox)
DESCRIPTION
ISNEAR determines if two numbers are near each other as defined by prox
ARGUMENTS
a ... first value
b ... 2nd value
prox ... proximity value
RETURNS
r ... 0 if no, 1 if yes
Created by Phil Dixon April 19th 2012