function determinant (u,v,w)
{
//***********************************************************************
//*
//* Function   determinant calculates the determinant of a 3 x 3 matrix composed of column vectors u,v, and w
//*
//* Language:  JavaScript1.1
//*
//* Inputs:  colum vectors:
//*    u      3 entry vector of first column
//*    v      3 entry vector of second column
//*    w      3 entry vector of third column
//*
//* Returns:  value of the determinant
//*
//* Limitations:
//*
//* Author:
//*  Dr. Jim Weaver
//*  Hydrologist
//*  Regulatory Support Branch
//*  Ecosystems Research Division
//*  National Exposure Research Laboratory
//*  United States Environmental Protection Agency
//*  960 College Station Road
//*  Athens, Georgia 30605
//*  weaver.jim@epa.gov
//* 
//*
//* Reference:
//*  Flanagan, D., 1997, JavaScript: The Definitive Guide, 2ed, O'Reilly and Associates
//*
//* Created:  12-16-1999
//*
//* Required functions:
//*
//* Required scripts:
//*
//***********************************************************************
var d = 0;

d = u[0]*(v[1]*w[2] - v[2]*w[1]);
d = d - v[0]*(u[1]*w[2] - u[2]*w[1]);
d = d + w[0]*(u[1]*v[2] - u[2]*v[1]);

return d;
}