gusucode.com > symbolic工具箱matlab源码程序 > symbolic/@sym/cumprod.m
function r = cumprod(varargin) %CUMPROD Symbolic cumulative product of elements. % For vectors, CUMPROD(X) is a vector containing the cumulative product % of the elements of SYM X. For matrices, CUMPROD(X) is a matrix the % same size as X containing the cumulative products over each column. % % CUMPROD(X,DIM) works along the dimension DIM. % % CUMPROD(X,'reverse') and CUMPROD(X,DIM,'reverse') compute the cumulative % product starting at the upper end of the index range. % % Example: % X = sym([0, 1, 2; 3, 4, 5]); % % r = cumprod(X) % returns r = [0, 1, 2; 0, 4, 10] % % r = cumprod(X,2) % returns r = [0, 0, 0; 3, 12, 60] % % syms x y; % X = [x, 2*x+1, 3*x+2; 1/y, y, 2*y]; % % r = cumprod(X) % returns r = [x, 2*x+1, 3*x+2; x/y, y*(2*x+1), 2*y*(3*x+2)] % % r = cumprod(X,'reverse') % returns r = [x/y, y*(2*x+1), 2*y*(3*x+2); 1/y, y, 2*y] % % r = cumprod(X,2) % returns r = [x, x*(2*x+1), x*(2*x+1)*(3*x+2); 1/y, 1, 2*y] % % r = cumprod(X,2,'reverse') % returns r = [x*(2*x+1)*(3*x+2), (2*x+1)*(3*x+2), 3*x+2; 2*y, 2*y^2, 2*y] % % See also CUMSUM, PROD, SUM, SYMPROD, SYMSUM, SYM/INT. % Copyright 2012-2014 The MathWorks, Inc. narginchk(1,3); r = cumsumprod('_mult', varargin{:});