function z=mmintgrl(x,y)%MMINTGRL Compute Integral using Trapezoidal Rule.% MMINTGRL(X,Y) computes the integral of the function y=f(x) given the% data in X and Y. X must be a vector, but Y may be a column oriented% data matrix. The length of X must equal the length of Y if Y is a% vector, or it must equal the number of rows in Y if Y is a matrix.%% X need not be equally spaced. The trapezoidal algorithm is used.%% See also mmderiv% D.C. Hanselman, University of Maine, Orono, ME 04469% 1/29/95% Copyright (c) 1996 by Prentice-Hall, Inc. flag=0;					% flag is true if y is a rowx=x(:);nx=length(x);	% make x a column[ry,cy]=size(y);if ry==1&cy==nx,y=y.';ry=cy;cy=1;flag=1;endif nx~=ry, error('X and Y not the right size'),enddx=x(2:nx)-x(1:nx-1);	% width of each trapezoiddx=dx(:,ones(1,cy));	% duplicate for each column in yyave=(y(2:ry,:)+y(1:ry-1,:))/2; % average of heightsz=[zeros(1,cy); cumsum(dx.*yave)];if flag,z=z';end		% if y was a row, return a row