I am testing a program which diagnalize a hermitian matrix, using LAPACKE_zheev function describe in the MKL manual.

When I try to compile this program, using **gcc myprogram.c** command. I got an error message saying that:

**/tmp/cc4Xdq1R.o: In function `diag':**

**zheev_mkl.c:(.text+0x3c): undefined reference to `LAPACKE_zheev'**

**collect2: ld returned 1 exit status**

I don't know how to solve this problem. I have used fortran zheev(F77) and heev(F90) before, and I succeed in compiling the program. In fortran program I use ifort compiler when using F77 interface I just type **ifort myprogram.f . **Using F90 interface I have a Makefile which is complicated and not written by myself. I will paste that to provide more information to you.

By the way, in my Unbuntu system, I have only installed the intel fortran composer, i didn't install any C compiler other than gcc and g++.

Here is my C program I want to compile:

#include <complex.h> #include <math.h> #include <stdlib.h> #include <stdint.h> #include <stdio.h> #include <mkl.h> lapack_int LAPACKE_zheev( int matrix_order, char jobz, char uplo, lapack_int n, lapack_complex_double* a, lapack_int lda, double* w ); //hermitian matrix, each row in output is an eigenvector, the input matrix is stored in column-major void diag(lapack_complex_double *mat, double *e, lapack_int n) { char jobz='V'; //also eigenvectors char uplo='U'; //upper triangle lapack_int info; info=LAPACKE_zheev(n,jobz,uplo,n,mat,n,e); if(info!=0){ printf("matrix diag fail\n"); exit(1); } } int main() { lapack_complex_double *mat; double *e; mat=(lapack_complex_double *)malloc(sizeof(lapack_complex_double)*16); e=(double *)malloc(sizeof(double)*4); mat[0].real=1.0; mat[0].imag=0.0; mat[1].real=1.0; mat[1].imag=-1.0; mat[2].real=1.0; mat[2].imag=-2.0; mat[3].real=1.0; mat[3].imag=-3.0; mat[4].real=1.0; mat[4].imag=1.0; mat[5].real=2.0; mat[5].imag=0.; mat[6].real=1.0; mat[6].imag=-4.0; mat[7].real=1.0; mat[7].imag=-5.0; mat[8].real=1.0; mat[8].imag=2.0; mat[9].real=1.0; mat[9].imag=4.0; mat[10].real=3.0; mat[10].imag=0.; mat[11].real=1.0; mat[11].imag=-6.0; mat[12].real=1.0; mat[12].imag=3.0; mat[13].real=1.0; mat[13].imag=5.0; mat[14].real=1.0; mat[14].imag=6.0; mat[15].real=4.0; mat[15].imag=0.; diag(mat,e,4); printf("the eigenvalue is %f,%f,%f,%f\n",e[1],e[2],e[3],e[4]); printf(" "); free(mat); free(e); }

And Here is my fortran Makefile which I think may provide some useful information:

NAME=zg OBJECTS = $(NAME).f90 cc = ifort MKLPATH=/opt/intel/composer_xe_2013.5.192/mkl/lib/intel64 MKLINCLUDE=/opt/intel/composer_xe_2013.5.192/mkl/include MODPATH=/opt/intel/composer_xe_2013.5.192/mkl/include/intel64/lp64 FLAGS= -module $(MODPATH) \ -assume byterecl -L$(MKLPATH) -I$(MKLINCLUDE) -I$(MODPATH) -lmkl_lapack95_lp64 -lmkl_blas95_lp64 -Wl,--start-group $(MKLPATH)/libmkl_intel_lp64.a $(MKLPATH)/libmkl_intel_thread.a $(MKLPATH)/libmkl_core.a -Wl,--end-group -liomp5 -lpthread OUTNAME=zg.out $(NAME): $(OBJECTS) $(cc) -o $(OUTNAME) $(OBJECTS) $(FLAGS) clean: rm -f $(OUTNAME)

Thanks for you help in advance.