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1.  新建normalizecolsmx.c文件

/* normalizecolsmx.c Normalize the columns of a matrixSyntax: B = normalizecols(A)or B = normalizecols(A,p)The columns of matrix A are normalized so that norm(B(:,n),p) = 1. */#include 
   
    #include "mex.h"#define IS_REAL_2D_FULL_DOUBLE(P) (!mxIsComplex(P) && mxGetNumberOfDimensions(P) == 2 && !mxIsSparse(P) && mxIsDouble(P))#define IS_REAL_SCALAR(R) (IS_REAL_2D_FULL_DOUBLE(P) && mxGetNumberOfElements(P) == 1)void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[]){	#define B_OUT		plhs[0]	#define A_IN		prhs[0]	#define P_IN		prhs[1]	double *B, *A, p, colnorm;	int M, N, m, n;		if( nrhs < 1 || nrhs > 2)		mexErrMsgTxt("Wrong number of input arguments.");	else if(nlhs > 1)		mexErrMsgTxt("Too many output arguements");		if( !IS_REAL_2D_FULL_DOUBLE(A_IN) )		mexErrMsgTxt("A must be a real 2D full double array.");		if( nrhs == 1)		p = 2.0;	else		p = mxGetScalar(P_IN);		M = mxGetM(A_IN);	N = mxGetN(A_IN);	A = mxGetPr(A_IN);	B_OUT = mxCreateDoubleMatrix(M, N, mxREAL);	B = mxGetPr(B_OUT);		for(n = 0; n < N; n++)	{		for(m = 0, colnorm = 0.0; m < M; m++)			colnorm += pow(A[m + M*n], p);		colnorm = pow( fabs(colnorm), 1.0/p);				for(m = 0; m < M; m++)			B[m + M * n] = A[m + M * n]/colnorm;			}	return ;}
   

2. 编译normalizecolsmx.c 文件

mex normalizecolsmx.c

%normalizecols.mfunction B = normalizecols(A, p)    if nargin < 2        if nargin < 1            error('Not enough input arguements');        end        p = 2;    end        if ~isreal(A) || ndims(A) ~= 2 || issparse(A) || ~isa(A, 'double')        error('A must be a real 2D full double array.');    elseif ~ isreal(p) || ~isa(p, 'double') || numel(p) ~= 1        error('P must be a real double scalar.');    end        B = normalizecolsmx(A, p);end