binomial.m

来自「多小波分析源码」· M 代码 · 共 36 行

function b = binomial(m,n)

% BINOMIAL --  binomial coefficient
% 
%        b = binomial(m,n)
%        
% Calculates the binomial coefficient
%
%            (m)      m!
%            (n) = ---------
%                  n! (m-n)!
% 
% m and n can be vectors or matrices, as long as one of them is a
% scalar, or they are both the same size.
%
% Examples:
%                               (5) (6) (7)
%        binomial([5,6,7],2) = [(2),(2),(2)]
%
%                               (5) (5) (5) 
%        binomial(5,[1,2,3]) = [(1),(2),(3)]
%
%                                     (5) (6) (7) 
%        binomial([5,6,7],[1,2,3]) = [(1),(2),(3)]

% Copyright (c) 2004 by Fritz Keinert ([e-mail]),
% Dept. of Mathematics, Iowa State University, Ames, IA 50011.
% This software may be freely used and distributed for non-commercial
% purposes, provided this copyright statement is preserved, and
% appropriate credit for its use is given.
%
% Last update: Feb 20, 2004

b = factorial(m) ./ (factorial(n) .* factorial(m-n));