function [magnitude]=mag(inVector, direction)
% MAG Returns the magnitude of a vector.
% MAG(VECTOR) is the total magnitude of the vector.
% MAG(VECTOR, 'x') is the magnitude in the X direction.
% MAG(VECTOR, 'y') is the magnitude in the Y direction.
% See also MOVE, OPP.
% Details are to be found in Mastering Mechanics I, Douglas W. Hull,
% Prentice Hall, 1998
% Douglas W. Hull, 1998
% Copyright (c) 1998-99 by Prentice Hall
% Version 1.00
[xmag ymag xcor ycor]=breakup(inVector);
if nargin == 1
direction = lower(direction);
magnitude=sqrt(xmag.^2 + ymag.^2);