MatDirBlk *mat_rdirblk(MatrixFile *file, int blknum) {
MatDirBlk *matdirblk;
int i, j, err, ndirs;
int dirbufr[MatBLKSIZE / 4];
FILE *fptr = file->fptr;
matrix_errno = MAT_OK;
matrix_errtxt[0] = '\0';
matdirblk = (MatDirBlk *) malloc(MatBLKSIZE);
if (matdirblk == NULL)
return (NULL);
err = read_matrix_data(fptr, blknum, 1, (char *) dirbufr, SunLong);
if (err == ERROR) {
free(matdirblk);
return (NULL);
}
matdirblk->nfree = dirbufr[0];
matdirblk->nextblk = dirbufr[1];
matdirblk->prvblk = dirbufr[2];
matdirblk->nused = dirbufr[3];
if (matdirblk->nused > 31) {
matrix_errno = MAT_INVALID_DIRBLK;
free(matdirblk);
return (NULL);
}
ndirs = (MatBLKSIZE / 4 - 4) / 4;
for (i = 0; i < ndirs; i++) {
matdirblk->matdir[i].matnum = 0;
matdirblk->matdir[i].strtblk = 0;
matdirblk->matdir[i].endblk = 0;
matdirblk->matdir[i].matstat = 0;
}
for (i = 0; i < matdirblk->nused; i++) {
j = i + 1;
matdirblk->matdir[i].matnum = dirbufr[j * 4 + 0];
matdirblk->matdir[i].strtblk = dirbufr[j * 4 + 1];
matdirblk->matdir[i].endblk = dirbufr[j * 4 + 2];
matdirblk->matdir[i].matstat = dirbufr[j * 4 + 3];
}
return (matdirblk);
}
/**
* Reads two matrices from the file and:
* - performs qr decomposition on the first matrix U
* - prints q and r to the console
* - performs qr iterations on the second matrix A
* - prints its eigen values to the console
*
* Matrix input format for both matrices is:
* The first line has m and n indicating number of rows and columns.
* Each of the next m lines contains n floats indicating the rows of the matrix.
*
* Sample input:
* 3 3
* 1.0 1.0 0.0
* 1.0 2.0 1.0
* -2.0 -3.0 1.0
* 2 2
* 7.0 2.0
* 2.0 4.0
*/
int main(int argc, char **argv)
{
FILE* fp = NULL;
matrix* u = NULL;
matrix* q = NULL;
matrix* r = NULL;
matrix* a = NULL;
matrix* a_k = NULL;
size_t m, n;
/* Read the input. */
fp = fopen("input.txt", "r");
if (fp == NULL)
{
perror("Failed to open input.txt");
exit(EXIT_FAILURE);
}
/* Read the dimensions of the matrix U. */
fscanf(fp, "%zu %zu", &m, &n);
/* Alloate the matrices U Q and R. */
u = new_matrix(m, n);
q = new_matrix(m, n);
r = new_matrix(m, n);
/* Read matrix data. */
read_matrix_data(fp, u);
/* Perform qr decomposition. */
qr_decomposition(u, q, r);
/* Print the matrices. */
printf("QR decomposition:\n");
printf("U:\n");
print_matrix_data(stdout, u);
printf("Q:\n");
print_matrix_data(stdout, q);
printf("R:\n");
print_matrix_data(stdout, r);
/* Free memory occupied by q and r. */
destroy_matrix(u);
destroy_matrix(q);
destroy_matrix(r);
/* Read the dimensions of the matrix A. */
fscanf(fp, "%zu %zu", &m, &n);
/* Allocate a vector for storing eigen values and matrices A and A_k */
a = new_matrix(m, n);
a_k = new_matrix(m, n);
float eigen_values[m];
/* Read matix data. */
read_matrix_data(fp, a);
/* Perform qr iterations. */
qr_iterations(a, a_k);
/* Extract the eigen values. */
extract_diagonal(a_k, eigen_values, m);
/* Print the matrix A and its eigen values. */
printf("\nQR iterations:\n");
printf("A:\n");
print_matrix_data(stdout, a);
printf("Eigen values:\n");
print_vector(stdout, eigen_values, m);
/* free memory occupied by A and A_k. */
destroy_matrix(a);
destroy_matrix(a_k);
/* Close the input file. */
fclose(fp);
return 0;
}
int mat_enter(FILE *fptr, Main_header *mhptr, int matnum, int nblks) {
int dirblk, dirbufr[128], i, nxtblk, busy, oldsize;
matrix_errno = MAT_OK;
matrix_errtxt[0] = '\0';
dirblk = MatFirstDirBlk;
if( fseek(fptr, 0, 0) ) return( ERROR );
/*
* nfs locks are very time consuming lockf( fileno(fptr), F_LOCK, 0);
*/
if (read_matrix_data(fptr, dirblk, 1, (char *) dirbufr, SunLong) == ERROR) return (ERROR);
busy = 1;
while (busy) {
nxtblk = dirblk + 1;
for (i = 4; i < 128; i += 4) {
if (dirbufr[i] == 0) {
busy = 0;
break;
} else if (dirbufr[i] == matnum) {
oldsize = dirbufr[i + 2] - dirbufr[i + 1] + 1;
if (oldsize < nblks) {
dirbufr[i] = 0xFFFFFFFF;
write_matrix_data(fptr, dirblk, 1, (char*)dirbufr, SunLong);
nxtblk = dirbufr[i + 2] + 1;
} else {
nxtblk = dirbufr[i + 1];
dirbufr[0]++;
dirbufr[3]--;
busy = 0;
break;
}
} else {
nxtblk = dirbufr[i + 2] + 1;
}
}
if (!busy) break;
if (dirbufr[1] != MatFirstDirBlk) {
dirblk = dirbufr[1];
if (read_matrix_data(fptr, dirblk, 1, (char *) dirbufr, SunLong) == ERROR) return (ERROR);
} else {
dirbufr[1] = nxtblk;
if (write_matrix_data(fptr, dirblk, 1, (char *) dirbufr, SunLong) == ERROR) return (ERROR);
dirbufr[0] = 31;
dirbufr[1] = MatFirstDirBlk;
dirbufr[2] = dirblk;
dirbufr[3] = 0;
dirblk = nxtblk;
for (i = 4; i < 128; i++)
dirbufr[i] = 0;
}
}
dirbufr[i] = matnum;
dirbufr[i + 1] = nxtblk;
dirbufr[i + 2] = nxtblk + nblks;
dirbufr[i + 3] = 1;
dirbufr[0]--;
dirbufr[3]++;
if (write_matrix_data(fptr, dirblk, 1, (char*)dirbufr, SunLong) == ERROR) return (ERROR);
if( fseek(fptr, 0, 0) ) return( ERROR );
/*
* nfs locks are very time consuming lockf( fileno(fptr), F_UNLOCK, 0);
*/
return (nxtblk);
}
