function som = integ(y,x) %INTEG	Approximate integral.%	SOM=INTEG(Y,X) approximates the integral of vector Y%	according to X.%%	Y   : N-row-vector (or MxN-matrix) to be integrated %	      (along each row).  %	X   : N-row-vector containing the integration path of Y%				(default : 1:N)%	SOM : value (or Mx1 vector) of the integral%%	Example :    %	 Y = altes(256,0.1,0.45,10000)'; X = (0:255);%	 SOM = integ(Y,X)%%	See also INTEG2D.%	P. Goncalves, October 95%	Copyright (c) 1995 Rice University%%	------------------- CONFIDENTIAL PROGRAM -------------------- %	This program can not be used without the authorization of its%	author(s). For any comment or bug report, please send e-mail to %	f.auger@ieee.org [M,N]=size(y);if nargin<1, error('At least one parameter required');elseif nargin==1, x=1:N;end[Mx,Nx]=size(x);if (Mx~=1), error('X must be a row-vector');elseif (N~=Nx), error('Y must have as many columns as X');elseif (N==1 & M>1), error('Y must be a row-vector or a matrix');end dy = y(:,1:N-1) + y(:,2:N) ;dx = (x(2:N)-x(1:N-1))/2 ;som = dy*dx';