Array subscript is not an integer
- by Dimitri
Hello folks, following this previous question Malloc Memory Corruption in C, now i have another problem.
I have the same code. Now I am trying to multiply the values contained in the arrays A * vc
and store in res. Then A is set to zero and i do a second multiplication with res and vc and i store the values in A. (A and Q are square matrices and mc and vc are N lines two columns matrices or arrays).
Here is my code :
int jacobi_gpu(double A[], double Q[],
double tol, long int dim){
int nrot, p, q, k, tid;
double c, s;
double *mc, *vc, *res;
int i,kc;
double vc1, vc2;
mc = (double *)malloc(2 * dim * sizeof(double));
vc = (double *)malloc(2 * dim * sizeof(double));
vc = (double *)malloc(dim * dim * sizeof(double));
if( mc == NULL || vc == NULL){
fprintf(stderr, "pb allocation matricre\n");
exit(1);
}
nrot = 0;
for(k = 0; k < dim - 1; k++){
eye(mc, dim);
eye(vc, dim);
for(tid = 0; tid < floor(dim /2); tid++){
p = (tid + k)%(dim - 1);
if(tid != 0)
q = (dim - tid + k - 1)%(dim - 1);
else
q = dim - 1;
printf("p = %d | q = %d\n", p, q);
if(fabs(A[p + q*dim]) > tol){
nrot++;
symschur2(A, dim, p, q, &c, &s);
mc[2*tid] = p; vc[2 * tid] = c;
mc[2*tid + 1] = q; vc[2*tid + 1] = -s;
mc[2*tid + 2*(dim - 2*tid) - 2] = p; vc[2*tid + 2*(dim - 2*tid) - 2 ] = s;
mc[2*tid + 2*(dim - 2*tid) - 1] = q; vc[2 * tid + 2*(dim - 2*tid) - 1 ] = c;
}
}
for( i = 0; i< dim; i++){
for(kc=0; kc < dim; kc++){
if( kc < floor(dim/2)) {
vc1 = vc[2*kc + i*dim];
vc2 = vc[2*kc + 2*(dim - 2*kc) - 2];
}else {
vc1 = vc[2*kc+1 + i*dim];
vc2 = vc[2*kc - 2*(dim - 2*kc) - 1];
}
res[kc + i*dim] = A[mc[2*kc] + i*dim]*vc1 + A[mc[2*kc + 1] + i*dim]*vc2;
}
}
zero(A, dim);
for( i = 0; i< dim; i++){
for(kc=0; kc < dim; k++){
if( k < floor(dim/2)){
vc1 = vc[2*kc + i*dim];
vc2 = vc[2*kc + 2*(dim - 2*kc) - 2];
}else {
vc1 = vc[2*kc+1 + i*dim];
vc2 = vc[2*kc - 2*(dim - 2*kc) - 1];
}
A[kc + i*dim] = res[mc[2*kc] + i*dim]*vc1 + res[mc[2*kc + 1] + i*dim]*vc2;
}
}
affiche(mc,dim,2,"Matrice creuse");
affiche(vc,dim,2,"Valeur creuse");
}
free(mc);
free(vc);
free(res);
return nrot;
}
When i try to compile, i have this error :
jacobi_gpu.c: In function ‘jacobi_gpu’:
jacobi_gpu.c:103: error: array subscript is not an integer
jacobi_gpu.c:103: error: array subscript is not an integer
jacobi_gpu.c:118: error: array subscript is not an integer
jacobi_gpu.c:118: error: array subscript is not an integer
make: *** [jacobi_gpu.o] Erreur 1
The corresponding lines are where I store the results in res and A :
res[kc + i*dim] = A[mc[2*kc] + i*dim]*vc1 + A[mc[2*kc + 1] + i*dim]*vc2;
and
A[kc + i*dim] = res[mc[2*kc] + i*dim]*vc1 + res[mc[2*kc + 1] + i*dim]*vc2;
Can someone explain me what is this error and how can i correct it?
Thanks for your help. ;)
