```/* nag_wav_dim2_sngl_fwd (c09eac) Example Program.
*
* Copyright 2019 Numerical Algorithms Group.
*
* Mark 27.0, 2019.
*/

#include <string.h>
#include <nag.h>

int main(void)
{
/* Scalars */
Integer exit_status = 0;
Integer i, j, m, n, nf, nwcm, nwcn, nwct, nwl, pda, pdb, pdc;
/* Arrays */
char mode[24], wavnam[20], title[50];
double *a = 0, *b = 0, *ca = 0, *cd = 0, *ch = 0, *cv = 0;
Integer icomm[(180)];
/* NAG types */
Nag_WaveletMode modenum;
Nag_MatrixType matrix = Nag_GeneralMatrix;
Nag_OrderType order = Nag_ColMajor;
Nag_DiagType diag = Nag_NonUnitDiag;
NagError fail;

INIT_FAIL(fail);

printf("nag_wav_dim2_sngl_fwd (c09eac) Example Program Results\n\n");

scanf("%*[^\n] %" NAG_IFMT "%" NAG_IFMT "%*[^\n]", &m, &n);
pda = m;
pdb = m;
scanf("%19s%23s%*[^\n]\n", wavnam, mode);
if (!(a = NAG_ALLOC((pda) * (n), double)) ||
!(b = NAG_ALLOC((pdb) * (n), double)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
printf(" Parameters read from file :: \n");
printf(" DWT :: Wavelet : %s\n", wavnam);
printf("        End mode: %s\n", mode);
fflush(stdout);

/*
* nag_enum_name_to_value (x04nac).
* Converts NAG enum member name to value
*/
modenum = (Nag_WaveletMode) nag_enum_name_to_value(mode);

#define A(I, J) a[(J-1)*pda + I-1]
for (i = 1; i <= m; i++)
for (j = 1; j <= n; j++)
scanf("%lf", &A(i, j));
scanf("%*[^\n] ");

printf("\n");
fflush(stdout);
nag_file_print_matrix_real_gen_comp(order, matrix, diag, m, n, a, pda, "%8.4f",
"Input Data     A :", Nag_NoLabels, 0,
Nag_NoLabels, 0, 80, 0, 0, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_file_print_matrix_real_gen_comp (x04cbc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
printf("\n");

/* nag_wav_dim2_init (c09abc).
* Two-dimensional wavelet filter initialization
*/
nag_wav_dim2_init(wavnamenum, Nag_SingleLevel, modenum, m, n, &nwl, &nf, &nwct,
&nwcn, icomm, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_wav_dim2_init (c09abc).\n%s\n", fail.message);
exit_status = 2;
goto END;
}
nwcm = nwct / (4 * nwcn);
if (!(ca = NAG_ALLOC((nwcm) * (nwcn), double)) ||
!(cd = NAG_ALLOC((nwcm) * (nwcn), double)) ||
!(cv = NAG_ALLOC((nwcm) * (nwcn), double)) ||
!(ch = NAG_ALLOC((nwcm) * (nwcn), double))
)
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}

pdc = nwcm;
/* nag_wav_dim2_sngl_fwd (c09eac).
* Two-dimensional discrete wavelet transform
*/
nag_wav_dim2_sngl_fwd(m, n, a, pda, ca, pdc, ch, pdc, cv, pdc, cd, pdc, icomm, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_wav_dim2_sngl_fwd (c09eac).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
fflush(stdout);

/* Print decomposition */
strcpy(title, "Approximation coefficients   CA :");
nag_file_print_matrix_real_gen_comp(order, matrix, diag, nwcm, nwcn, ca, pdc,
"%8.4f",
title, Nag_NoLabels, 0, Nag_NoLabels, 0, 80, 0,
0, &fail);
printf("\n");
fflush(stdout);
strcpy(title, "Diagonal coefficients        CD :");
nag_file_print_matrix_real_gen_comp(order, matrix, diag, nwcm, nwcn, cd, pdc,
"%8.4f",
title, Nag_NoLabels, 0, Nag_NoLabels, 0, 80, 0,
0, &fail);
printf("\n");
fflush(stdout);
strcpy(title, "Horizontal coefficients      CH :");
nag_file_print_matrix_real_gen_comp(order, matrix, diag, nwcm, nwcn, ch, pdc,
"%8.4f",
title, Nag_NoLabels, 0, Nag_NoLabels, 0, 80, 0,
0, &fail);
printf("\n");
fflush(stdout);
strcpy(title, "Vertical coefficients        CV :");
nag_file_print_matrix_real_gen_comp(order, matrix, diag, nwcm, nwcn, cv, pdc,
"%8.4f",
title, Nag_NoLabels, 0, Nag_NoLabels, 0, 80, 0,
0, &fail);
printf("\n");

/* nag_wav_dim2_sngl_inv (c09ebc).
* Two-dimensional inverse discrete wavelet transform
*/
nag_wav_dim2_sngl_inv(m, n, ca, pdc, ch, pdc, cv, pdc, cd, pdc, b, pdb, icomm, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_wav_dim2_sngl_inv (c09ebc).\n%s\n", fail.message);
exit_status = 3;
goto END;
}
fflush(stdout);

/* Print reconstruction */
strcpy(title, "Reconstruction                B :");
nag_file_print_matrix_real_gen_comp(order, matrix, diag, m, n, b, pdb, "%8.4f",
title,
Nag_NoLabels, 0, Nag_NoLabels, 0, 80, 0, 0,
&fail);
END:
NAG_FREE(a);
NAG_FREE(b);
NAG_FREE(ca);
NAG_FREE(cd);
NAG_FREE(ch);
NAG_FREE(cv);
return exit_status;
}
```