[37] | 1 | /* compile with: cmex gammaln.c mexutil.c util.c -lm |
---|
| 2 | * test in matlab: |
---|
| 3 | * gammaln(1:10) |
---|
| 4 | */ |
---|
| 5 | /* Written by Tom Minka |
---|
| 6 | * (c) Microsoft Corporation. All rights reserved. |
---|
| 7 | */ |
---|
| 8 | #include "mex.h" |
---|
| 9 | #include "util.h" |
---|
| 10 | |
---|
| 11 | void mexFunction(int nlhs, mxArray *plhs[], |
---|
| 12 | int nrhs, const mxArray *prhs[]) |
---|
| 13 | { |
---|
| 14 | int ndims, len, i; |
---|
| 15 | int *dims; |
---|
| 16 | double *indata, *outdata, d; |
---|
| 17 | |
---|
| 18 | if((nlhs > 1) || (nrhs < 1) || (nrhs > 2)) |
---|
| 19 | mexErrMsgTxt("Usage: x = gammaln(n) or gammaln(n,d)"); |
---|
| 20 | |
---|
| 21 | /* prhs[0] is first argument. |
---|
| 22 | * mxGetPr returns double* (data, col-major) |
---|
| 23 | */ |
---|
| 24 | ndims = mxGetNumberOfDimensions(prhs[0]); |
---|
| 25 | dims = (int*)mxGetDimensions(prhs[0]); |
---|
| 26 | indata = mxGetPr(prhs[0]); |
---|
| 27 | len = mxGetNumberOfElements(prhs[0]); |
---|
| 28 | |
---|
| 29 | if(mxIsSparse(prhs[0])) |
---|
| 30 | mexErrMsgTxt("Cannot handle sparse matrices. Sorry."); |
---|
| 31 | |
---|
| 32 | /* plhs[0] is first output */ |
---|
| 33 | plhs[0] = mxCreateNumericArray(ndims, dims, mxDOUBLE_CLASS, mxREAL); |
---|
| 34 | outdata = mxGetPr(plhs[0]); |
---|
| 35 | |
---|
| 36 | /* compute gammaln of every element */ |
---|
| 37 | if(nrhs == 1) { |
---|
| 38 | for(i=0;i<len;i++) |
---|
| 39 | *outdata++ = gammaln(*indata++); |
---|
| 40 | } else { |
---|
| 41 | d = *mxGetPr(prhs[1]); |
---|
| 42 | for(i=0;i<len;i++) |
---|
| 43 | *outdata++ = gammaln2(*indata++,d); |
---|
| 44 | } |
---|
| 45 | } |
---|
| 46 | |
---|