void cr2dfft(complex *cdata, REAL *rdata, int nr, int nc, int ldc, int ldr, int sign)
{
#if defined(HAVE_LIBSCS)
static int nr_prev=0, nc_prev=0;
int isys=0, ntable, nwork, zero=0;
int ld1, j;
static float *work, *table;
float scale=1.0;
#else
int i, j, nf;
complex *tmp;
#endif
#if defined(HAVE_LIBSCS)
if (nr != nr_prev || nc != nc_prev) {
nwork = nr*nc;
ntable = 15+nr+2*(15+nc);
if (work) free (work);
if (table) free (table);
work = (float *)malloc(nwork*sizeof(float));
table = (float *)malloc(ntable*sizeof(float));
csfft2d_(&zero,&nr,&nc,&scale,cdata,&ldc,rdata,&ldr,table,work,&isys);
nr_prev = nr;
nc_prev = nc;
}
ld1 = 2*ldc;
csfft2d_(sign,&nr,&nc,&scale,cdata,&ldc,cdata,&ld1,table,work,&isys);
for (j=0; j<nc; j++) {
memcpy((float *)&rdata[j*ldr], (float *)&cdata[j*ldc].r, sizeof(float)*nr);
}
#else
tmp = (complex *)malloc(nc*sizeof(complex));
nf = (nr+2)/2;
for (i=0; i<nf; i++) {
for (j=0; j<nc; j++) tmp[j] = cdata[j*ldc+i];
cc1fft(tmp, nc, sign);
for (j=0; j<nc; j++) cdata[j*ldc+i] = tmp[j];
}
free (tmp);
crmfft(cdata, rdata, nr, nc, ldc, ldr, sign);
#endif
return;
}
void ncrmfft(complex *cdata, REAL *rdata, int *n1, int *n2, int *ldc, int *ldr, int *sign)
{
crmfft(cdata, rdata, *n1, *n2, *ldc, *ldr, *sign);
return;
}
void convolhom(float *data1, float *data2, float *con, int nrec, int nsam, float dt, int shift, float rho, int mode)
{
int i, j, n, optn, nfreq, sign;
float df, dw, om, tau, scl;
float *qr, *qi, *p1r, *p1i, *p2r, *p2i, *rdata1, *rdata2;
complex *cdata1, *cdata2, *ccon, tmp;
optn = optncr(nsam);
nfreq = optn/2+1;
cdata1 = (complex *)malloc(nfreq*nrec*sizeof(complex));
if (cdata1 == NULL) verr("memory allocation error for cdata1");
cdata2 = (complex *)malloc(nfreq*nrec*sizeof(complex));
if (cdata2 == NULL) verr("memory allocation error for cdata2");
ccon = (complex *)malloc(nfreq*nrec*sizeof(complex));
if (ccon == NULL) verr("memory allocation error for ccov");
rdata1 = (float *)malloc(optn*nrec*sizeof(float));
if (rdata1 == NULL) verr("memory allocation error for rdata1");
rdata2 = (float *)malloc(optn*nrec*sizeof(float));
if (rdata2 == NULL) verr("memory allocation error for rdata2");
/* pad zeroes until Fourier length is reached */
pad_data(data1, nsam, nrec, optn, rdata1);
pad_data(data2, nsam, nrec, optn, rdata2);
/* forward time-frequency FFT */
sign = -1;
rcmfft(&rdata1[0], &cdata1[0], optn, nrec, optn, nfreq, sign);
rcmfft(&rdata2[0], &cdata2[0], optn, nrec, optn, nfreq, sign);
/* apply convolution */
p1r = (float *) &cdata1[0];
p2r = (float *) &cdata2[0];
qr = (float *) &ccon[0].r;
p1i = p1r + 1;
p2i = p2r + 1;
qi = qr + 1;
n = nrec*nfreq;
for (j = 0; j < n; j++) {
*qr = (*p2r**p1r-*p2i**p1i);
*qi = (*p2r**p1i+*p2i**p1r);
qr += 2;
qi += 2;
p1r += 2;
p1i += 2;
p2r += 2;
p2i += 2;
}
free(cdata1);
free(cdata2);
if (shift) {
df = 1.0/(dt*optn);
dw = 2*PI*df;
tau = dt*(nsam/2);
for (j = 0; j < nrec; j++) {
om = 0.0;
for (i = 0; i < nfreq; i++) {
tmp.r = ccon[j*nfreq+i].r*cos(om*tau) + ccon[j*nfreq+i].i*sin(om*tau);
tmp.i = ccon[j*nfreq+i].i*cos(om*tau) - ccon[j*nfreq+i].r*sin(om*tau);
ccon[j*nfreq+i] = tmp;
om += dw;
}
}
}
/* Scaling for the homogeneous equation */
if (mode==0) {//single source
df = 1.0/(dt*optn);
dw = 2.0*(M_PI)*df;
for (i=0; i<nrec; i++) {
j=0;
ccon[i*nfreq+j].r *= 0.0;
ccon[i*nfreq+j].i *= 0.0;
for (j=1; j<nfreq; j++) {
ccon[i*nfreq+j].r *= (4.0/(rho*dw*j));
ccon[i*nfreq+j].i *= (4.0/(rho*dw*j));
}
}
}
else {//multiple sources
df = 1.0/(dt*optn);
dw = 2.0*(M_PI)*df;
for (i=0; i<nrec; i++) {
j=0;
ccon[i*nfreq+j].r *= 0.0;
ccon[i*nfreq+j].i *= 0.0;
for (j=1; j<nfreq; j++) {
tmp.r = (2.0/(rho*dw*j))*ccon[i*nfreq+j].i;
tmp.i = (2.0/(rho*dw*j))*ccon[i*nfreq+j].r;
ccon[i*nfreq+j]=tmp;
}
}
}
/* inverse frequency-time FFT and scale result */
sign = 1;
scl = 1.0/((float)(optn));
crmfft(&ccon[0], &rdata1[0], optn, nrec, nfreq, optn, sign);
scl_data(rdata1,optn,nrec,scl,con,nsam);
free(ccon);
free(rdata1);
free(rdata2);
return;
}
