排列组合问题在MATLAB中的实现方法大全

1、排列组合问题在 MATLAB 中的实现方法大全 matlab 做排列组合：比如要 ABCD 的全排列，可以用 perms 函数 perms(ABCD) 运行结果DCBADCABDBCADBACDABCDACBCDBACDABCBDACBADCABDCADBBCDABCADBDCABDACBADCBACDACBDACDBABCDABDCADBCADCB以下是几个常用的排列、组合与阶乘等函数。1、combntns(x,m)列举出从 n 个元素中取出 m 个元素的组合。其中， x 是含有 n 个元素的向量。2、perms(x) 给出向量 x 的所有排列。3、nchoosek(n,m)从 n 各元素中

2、取 m 个元素的所有组合数。 nchoosek(x,m) 从向量 x 中取 m 个元素的组合4、factorial(n) 求 n 的阶乘。% 求(2n-1)!或(2n)!5、 prod(n:m)% 求排列数：m*(m-1)*(m-2)* *(n+1)*n prod(1:2:2n-1)或 prod(2:2:2n)6、cumprod(n:m)输出一个向量 n n*(n+1) n(n+1)(n+2) n(n+1)(n+2) (m-1)m7、gamma(n)求 n!8、v=n!;vpa(v)更详细资料如下nchoosekBinomial coefficient or all combinationsS

3、yntax:C = nchoosek(n,k)函数描述： 从n个元素中一次选k个元素的所有组合数 C (注意，C是一个数值)。C = n!/(n - k)! k!);C = nchoosek(v,k)函数描述：从向量v中一次选其中k个元素的所有组合C (注意：C是一个矩阵，列数 为k )DescriptionC = nchoosek(n,k)where n and k are nonnegative integers,returns n!/(n - k)! k!).This is the number of combinations of n things taken k at a time.

4、C = nchoosek(v,k),where v is a row vector of length n,creates a matrix whose rows consist of all possible combinations of the n elements of v taken k at a time.Matrix C con tai ns n!/(n - k)! k!) rows and k colum ns.Inputs n, k, and v support classes of float double and float single.Examples：The com

5、mand nchoosek(2：2：10,4)returns the even numbers from two to ten, taken four at a time：246824610248102681046810combntnsAll possible combinations of set of values从给定集合 set中列出所有可能的subset个元素的组合Syntaxcombos = combntns(set,subset)combos = combntns(set,subset) returns a matrix whose rows are the various co

6、mbinations that can be taken of the elements of the vector set of length subset.Many combinatorial applications can make use of a vector 1：n for the input set to return generalized, indexed combination subsets.DescriptionThe combntns function provides the combinatorial subsets of a set of numbers.It

7、 is similar to the mathematical expression a choose b, except that instead of the number of such combinations,the actual combinations are returned. In combinatorial counting, the ordering of the values is not significant.The numerical value of the mathematical statement a choose b is size(combo s,1).ExamplesHow can the numbers 1 to 5 be taken in sets of three (that is, whatis 5 choose 3)?combos = combntns(1：5,3)combos =1 2 31 21 31 31 42 32 32 43 4 size(combos,1) ans =54554555% 5 choose 310( 注意事项 )： Note that if a val