mxCallMATLAB problems
in [Matlab]
|
Prev: randomly moving spheres
Next: hmm, initial matrix
From: Kimonas Fountoulakis on 7 Jun 2010 15:49 Hi I have a mex file and I am trying to use some Matlab function in it by using the mxCallMATLAB function. A part of my program is: #include <stdlib.h> #include <stdio.h> #include <string.h> #include <math.h> #include "../../interface/Lp.h" #include "../../interface/mps.h" #include "myallocator.h" #include "mex.h" /* A complete example of how to solve an LP problem with HOPDM. The LP problem is loaded directly into HOPDM data structures. The problem min -3 * x1 + 5 * x2 s. to x1 + 6 * x2 <= 6 -10 <= x1 <= 20 0 <= x2 <= 30 has unique solution x1 = 6, x2 = 0, f(x_opt) = -18.0 */ /*-------------------- solve simple LP problem --------------------*/ void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[]) { long max_rows = mxGetScalar(prhs[0]); /* 10 */ long max_cols = mxGetScalar(prhs[1]); /* 20 */ long max_nzA = mxGetScalar(prhs[2]); /* 50 */ long max_nzQ = mxGetScalar(prhs[3]); /* 50 */ long presolve = mxGetScalar(prhs[4]); /* 0 */ long irobj = mxGetScalar(prhs[5]); /* -1 */ long iolog = mxGetScalar(prhs[6]); /* 77 */ long restart = mxGetScalar(prhs[7]); /* 0 */ long iexit; long iters; double opt_tol; long errorb; long erroru; long errorc; long asmall; long alarge; double mult = mxGetScalar(prhs[16]); /* 1. */ long big = mxGetScalar(prhs[17]); /* 1.e30 */ long z_opt; int i; int code; MPS *P; Lp *my_Pb; Lp_save *L_save; L_save = VECT (Lp_save, 1); mxArray *lhs[5]; mxArray *rhs; rhs = mxCreateDoubleMatrix(6, 1, mxREAL); double *x = mxGetPr(rhs); x[0] = 2; x[1] = 2; x[2] = 2; x[3] = 0; x[4] = 0; x[5] = 0; x[6] = 0; mexCallMATLAB(5, &lhs, 6, &rhs, "getData"); /* HERE IS THE WARNING */ /* mexCallMATLAB(0, NULL, 1, &rhs, "disp"); */ the function that I am trying to use is: [A,b,xs,xsn,picks] = getData(m,n,k,Ameth,xmeth,varargin) and the warning is: MexSmallLP1.c:82: warning: passing argument 2 of ‘mexCallMATLAB’ from incompatible pointer type /home/kfoynt/Desktop/matlab/extern/include/mex.h:252: note: expected ‘struct mxArray **’ but argument is of type ‘struct mxArray * (*)[5]’ After I am trying to use my MEX file, the matlab crashes and forces me to restart it. If I remove the line 82 everything works fine!
From: James Tursa on 7 Jun 2010 17:05 "Kimonas Fountoulakis" <kfoynt(a)hotmail.com> wrote in message <hujifh$7t9$1(a)fred.mathworks.com>... > > mxArray *lhs[5]; > mxArray *rhs; > rhs = mxCreateDoubleMatrix(6, 1, mxREAL); > double *x = mxGetPr(rhs); : > mexCallMATLAB(5, &lhs, 6, &rhs, "getData"); /* HERE IS THE WARNING */ : > mexCallMATLAB(0, NULL, 1, &rhs, "disp"); > > the function that I am trying to use is: > [A,b,xs,xsn,picks] = getData(m,n,k,Ameth,xmeth,varargin) To make the above call correctly, set things up as follows: int i; mxArray *lhs[5]; mxArray *rhs[6]; rhs[0] = whatever; : rhs[5] = whatever; : mexCallMATLAB(5, lhs, 6, rhs, "getData"); : mexCallMATLAB(0, NULL, 1, lhs, "disp"); // display 1st output item : for( i=0; i<5; i++ ) { mxDestroyArray(lhs[i]); } for( i=0; i<6; i++ ) { mxDestroyArray(rhs[i]); } James Tursa
From: James Tursa on 7 Jun 2010 17:14 "Kimonas Fountoulakis" <kfoynt(a)hotmail.com> wrote in message <hujifh$7t9$1(a)fred.mathworks.com>... > > mxArray *lhs[5]; > mxArray *rhs; > rhs = mxCreateDoubleMatrix(6, 1, mxREAL); > double *x = mxGetPr(rhs); > > x[0] = 2; x[1] = 2; x[2] = 2; x[3] = 0; x[4] = 0; x[5] = 0; x[6] = 0; > > mexCallMATLAB(5, &lhs, 6, &rhs, "getData"); /* HERE IS THE WARNING */ I just noticed that it appears you are trying to use the pr data area of rhs[0] as the 6 inputs (although you tried to fill 7 of them) to your getData function. You can't do it this way. You have to create them individually. e.g., mxArray *lhs[5]; mxArray *rhs[6]; : rhs[0] = mxCreateDoubleScalar(2); rhs[1] = mxCreateDoubleScalar(2); rhs[2] = mxCreateDoubleScalar(2); rhs[3] = mxCreateDoubleScalar(0); rhs[4] = mxCreateDoubleScalar(0); rhs[5] = mxCreateDoubleScalar(0); : mexCallMATLAB(5, lhs, 6, rhs, "getData"); James Tursa
From: Kimonas Fountoulakis on 7 Jun 2010 17:36 Thank you my friend.. but... it didnt work. I am giving you again my code: mxArray *lhs[5]; mxArray *rhs; rhs = mxCreateDoubleMatrix(6, 1, mxREAL); double *x = mxGetPr(rhs); x[0] = 2; x[1] = 2; x[2] = 2; x[3] = 0; x[4] = 0; x[5] = 0; mexCallMATLAB(5, lhs, 6, rhs, "getData"); /* mexCallMATLAB(0, NULL, 1, &rhs, "disp"); */ It gives me the warning for the second argument of the first mexCallMATLAB call. It compiles normally but if I try to run my program the matlab crashes. I tested the rhs variable by printing it (see /* comments */ ) and it works fine, the problem for the lhs variable. "James Tursa" <aclassyguy_with_a_k_not_a_c(a)hotmail.com> wrote in message <hujmug$bpv$1(a)fred.mathworks.com>... > "Kimonas Fountoulakis" <kfoynt(a)hotmail.com> wrote in message <hujifh$7t9$1(a)fred.mathworks.com>... > > > > mxArray *lhs[5]; > > mxArray *rhs; > > rhs = mxCreateDoubleMatrix(6, 1, mxREAL); > > double *x = mxGetPr(rhs); > : > > mexCallMATLAB(5, &lhs, 6, &rhs, "getData"); /* HERE IS THE WARNING */ > : > > mexCallMATLAB(0, NULL, 1, &rhs, "disp"); > > > > the function that I am trying to use is: > > [A,b,xs,xsn,picks] = getData(m,n,k,Ameth,xmeth,varargin) > > To make the above call correctly, set things up as follows: > > int i; > mxArray *lhs[5]; > mxArray *rhs[6]; > rhs[0] = whatever; > : > rhs[5] = whatever; > : > mexCallMATLAB(5, lhs, 6, rhs, "getData"); > : > mexCallMATLAB(0, NULL, 1, lhs, "disp"); // display 1st output item > : > for( i=0; i<5; i++ ) { > mxDestroyArray(lhs[i]); > } > for( i=0; i<6; i++ ) { > mxDestroyArray(rhs[i]); > } > > > James Tursa
From: Kimonas Fountoulakis on 7 Jun 2010 17:43
It worked!!!!!!! THANKS!! pls, coud you explain me why this doesn't work?? mxArray *lhs[5]; mxArray *rhs; rhs = mxCreateDoubleMatrix(6, 1, mxREAL); double *x = mxGetPr(rhs); x[0] = 2; x[1] = 2; x[2] = 2; x[3] = 0; x[4] = 0; x[5] = 0; mexCallMATLAB(5, lhs, 6, rhs, "getData"); Is there a problem if I declare rhs as a matrix pass it into the x pointer, and pass the values into the memory through x??? and if yes, why?? Thanks again!! "James Tursa" <aclassyguy_with_a_k_not_a_c(a)hotmail.com> wrote in message <hujnes$797$1(a)fred.mathworks.com>... > "Kimonas Fountoulakis" <kfoynt(a)hotmail.com> wrote in message <hujifh$7t9$1(a)fred.mathworks.com>... > > > > mxArray *lhs[5]; > > mxArray *rhs; > > rhs = mxCreateDoubleMatrix(6, 1, mxREAL); > > double *x = mxGetPr(rhs); > > > > x[0] = 2; x[1] = 2; x[2] = 2; x[3] = 0; x[4] = 0; x[5] = 0; x[6] = 0; > > > > mexCallMATLAB(5, &lhs, 6, &rhs, "getData"); /* HERE IS THE WARNING */ > > I just noticed that it appears you are trying to use the pr data area of rhs[0] as the 6 inputs (although you tried to fill 7 of them) to your getData function. You can't do it this way. You have to create them individually. e.g., > > mxArray *lhs[5]; > mxArray *rhs[6]; > : > rhs[0] = mxCreateDoubleScalar(2); > rhs[1] = mxCreateDoubleScalar(2); > rhs[2] = mxCreateDoubleScalar(2); > rhs[3] = mxCreateDoubleScalar(0); > rhs[4] = mxCreateDoubleScalar(0); > rhs[5] = mxCreateDoubleScalar(0); > : > mexCallMATLAB(5, lhs, 6, rhs, "getData"); > > James Tursa |