static void ifftx(complex_t data[], complex_t temp[], int n)
{
int i;
int h;
int p;
int t;
int i2;
complex_t wkt;
if (n > 1)
{
h = n/2;
for (i = 0; i < h; i++)
{
i2 = i*2;
temp[i] = data[i2]; /* Even */
temp[h + i] = data[i2 + 1]; /* Odd */
}
fftx(&temp[0], &data[0], h);
fftx(&temp[h], &data[h], h);
p = 0;
t = MAX_FFT_LEN/n;
for (i = 0; i < h; i++)
{
wkt = complex_mul(île[p], &temp[h + i]);
data[i] = complex_add(&temp[i], &wkt);
data[h + i] = complex_sub(&temp[i], &wkt);
p += t;
}
}
}
void ifft(complex_t data[], int len)
{
int i;
double x;
complex_t temp[MAX_FFT_LEN];
/* A very slow and clunky FFT, that's just fine for filter design. */
for (i = 0; i < MAX_FFT_LEN/2; i++)
{
x = (2.0*3.1415926535*i)/(double) MAX_FFT_LEN;
circle[i] = expj(x);
}
fftx(data, temp, len);
}
SPAN_DECLARE(void) fft(complex_t data[], int len)
{
int i;
double x;
complex_t temp[MAX_FFT_LEN];
/* A very slow and clunky FFT, that's just fine for tests. */
if (!circle_init)
{
for (i = 0; i < MAX_FFT_LEN/2; i++)
{
x = -(2.0*3.1415926535*i)/(double) MAX_FFT_LEN;
circle[i] = expj(x);
}
circle_init = true;
}
fftx(data, temp, len);
}
static void outmap( fint lpt , /* number of points in X */
fint mpt , /* number of points in Y */
fint lmin , /* lower x map coordinate */
fint mmin , /* lower y map coordinate */
fchar set[] , /* set name */
fint sub[] , /* subset levels */
fint nset , /* number of sets */
fint modo ) /* output mode, amp./pha. or cos./sin. */
{
fint i, itab, k, m, md, mi, mj, ms, mph, mphh;
fint q, r, ri, rj, rs, row;
fint n;
fint count[MAXSET], nblank[MAXSET];
float rbuf[2*SIZE], cbuf[2*SIZE];
float datamax[MAXSET], datamin[MAXSET];
float fr, fi, zr, zi;
for ( k = 0; k < nset; count[k++] = 0 );
if ( FORM == -1 ) { /* complex ---FFT---> real */
k = 0; /* set number */
rs = MIN( mpt, ( 2 * SIZE ) / lpt ); /* number of rows per pass */
for ( r = 0 ; r < mpt; r += rs ) {/* loop to get data from scratch file */
getrow( rbuf, rs * lpt, r / rs );
md = 0;
do {
m = shiftr( mmin, mpt, r + md );
ms = MIN( rs - md, mpt + mmin - m );
i = md * lpt;
writxy( set[k], sub[k], lmin, m, &rbuf[i], lpt, ms );
md = md + ms;
} while ( md != rs );
n = lpt * rs;
minmax3_c( rbuf, &n, &datamin[k], &datamax[k], &nblank[k], &count[k] );
}
} else if ( FORM == 0 ) { /* real ---FFT---> complex */
q = POWTAB[ MAXP2 - LOGP2Y - 1 ]; /* table offset factor */
mph = mpt / 2; /* y-dimension of transform */
mphh = mph / 2 + 1;
getrow( cbuf, 2 * lpt, 0 ); /* create row MPH */
putrow( cbuf, 2 * lpt, mph );
fr = 0.5 * SIGN;
fi = 0.5;
for ( ri = 0; ri < mphh; ri++ ) {
rj = mph - ri;
itab = ri * q; /* calculate table position */
zr = 0.5 - fr * SINTAB[itab];
zi = fi * COSTAB[itab];
getrow( cbuf, 2 * lpt, ri );
getrow( rbuf, 2 * lpt, rj );
fxrl( zr, zi, cbuf, rbuf, ri, rj, lpt ); /* fixup real ---> complex */
fftx( cbuf ); /* do the FFT in x-direction */
vector( cbuf, lpt, 1, modo );
mi = shiftr( mmin, mpt, ri );
for ( k = 0; k < nset; k++ ) {
i = k * lpt;
writxy( set[k], sub[k], lmin, mi, &cbuf[i], lpt , 1 );
minmax3_c( &cbuf[i], &lpt, &datamin[k], &datamax[k], &nblank[k],
&count[k] );
}
if ( ri > 0 ) { /* do not double lines */
mirror( cbuf, lpt, -lmin );
mi = shiftr( mmin, mpt, mpt - ri );
for ( k = 0; k < nset; k++ ) {
i = k * lpt;
writxy( set[k], sub[k], lmin, mi, &cbuf[i], lpt, 1 );
minmax3_c( &cbuf[i], &lpt, &datamin[k], &datamax[k], &nblank[k],
&count[k] );
}
}
if ( ri == rj ) break; /* we've done it */
fftx( rbuf ); /* do the FFT in x-direction */
vector( rbuf, lpt, 1, modo );
mj = shiftr( mmin, mpt, rj );
for ( k = 0; k < nset; k++ ) {
i = k * lpt;
writxy( set[k], sub[k], lmin, mj, &rbuf[i], lpt, 1 );
minmax3_c( &rbuf[i], &lpt, &datamin[k], &datamax[k], &nblank[k],
&count[k] );
}
if ( rj < mph ) { /* do not double lines */
mirror( rbuf, lpt, -lmin );
mj = shiftr( mmin, mpt, mpt - rj );
for ( k = 0; k < nset; k++ ) {
i = k * lpt;
writxy( set[k], sub[k], lmin, mj, &rbuf[i], lpt, 1 );
minmax3_c( &rbuf[i], &lpt, &datamin[k], &datamax[k], &nblank[k],
&count[k] );
}
}
}
} else if ( FORM == 1 ) { /* complex ---FFT---> complex */
for ( row = 0; row < mpt; row++ ) {
getrow( cbuf, 2 * lpt, row );
vector( cbuf, lpt, 1, modo );
m = shiftr( mmin, mpt, row );
for ( k = 0; k < nset; k++ ) {
i = k * lpt;
writxy( set[k], sub[k], lmin, m, &cbuf[i], lpt, 1 );
minmax3_c( &cbuf[i], &lpt, &datamin[k], &datamax[k], &nblank[k],
&count[k] );
}
}
}
{
fint change = 1;
fint one = 1;
for ( k = 0; k < nset; k++ ) {
wminmax_c( set[k], &sub[k], &datamin[k], &datamax[k],
&nblank[k], &one, &change );
}
}
}
static void inpmap( fint lpt , /* number of points in X */
fint mpt , /* number of points in Y */
fint lmin , /* left most x map coordinate */
fint mmin , /* lower most y map coordinate */
fchar set[] , /* input set name */
fint sub[] , /* subsets */
fint nset , /* number of sets */
fint modi ) /* input mode, amp./pha. or cos./sin. */
{
fint i, itab, k, m, md, mi, mj, mph, mphh, ms;
fint q, r, ri, rj, row, rs, wor;
float rbuf[2*SIZE], cbuf[2*SIZE];
float fr, fi, zr, zi;
if ( FORM == -1 ) { /* complex ---FFT---> real */
q = POWTAB[ MAXP2 - LOGP2Y - 1 ]; /* table offset factor */
mph = mpt / 2; /* number of rows to load */
mphh = mph / 2 + 1;
fr = -0.5 * SIGN; /* calculate factors */
fi = -0.5;
for ( ri = 0 ; ri < mphh; ri++ ) { /* loop to load data */
rj = mph - ri;
itab = ri * q; /* get table position */
zr = 0.5 - fr * SINTAB[itab];
zi = fi * COSTAB[itab];
mi = shiftr( mmin, mpt, ri );
for ( k = 0; k < nset; k++ ) { /* get data */
i= k * lpt;
readxy( set[k], sub[k], lmin, mi, &cbuf[i], lpt, 1 );
}
mj = shiftr( mmin, mpt, rj );
for ( k = 0; k < nset; k++ ) { /* get data */
i = k * lpt;
readxy( set[k], sub[k], lmin, mj, &rbuf[i], lpt, 1 );
}
vector( cbuf, lpt, modi, 1 );
vector( rbuf, lpt, modi, 1 );
fftx( cbuf ); /* do the FFT */
fftx( rbuf );
/* fixup for complex to real transform */
fxrl( zr, zi, cbuf, rbuf, ri, rj, lpt );
/* store in scratch file */
wor = bitrev( ri, LOGP2Y );
putrow( cbuf, 2 * lpt, wor );
if ( ( ri != rj ) && ( ri != 0 ) ) {
wor = bitrev( rj, LOGP2Y );
putrow( rbuf, 2 * lpt, wor );
}
}
} else if ( FORM == 0 ) { /* real ---FFT---> complex */
rs = MIN( mpt, ( 2 * SIZE ) / lpt ); /* number of rows in one pass */
k = 0; /* subset number */
for ( r = 0; r < mpt; r += rs ) {/* loop to load data */
md = 0;
do {
m = shiftr( mmin, mpt, r + md );
ms = MIN( rs - md, mpt + mmin - m );
i = md * lpt;
readxy( set[k], sub[k], lmin, m, &cbuf[i], lpt, ms );
md = md + ms;
} while ( md != rs );
for ( row = r; row < ( r + rs ); row += 2 ) {
i = ( row - r ) * lpt;
wor = bitrev( row / 2, LOGP2Y );
putrow( &cbuf[i], 2 * lpt, wor );
}
}
} else if ( FORM == 1 ) { /* complex ---FFT---> complex */
for ( row = 0; row < mpt; row++ ) {
m = shiftr( mmin, mpt, row ); /* get data from disk */
for ( k = 0; k < nset; k++ ) {
i = k * lpt;
readxy( set[k], sub[k], lmin, m, &cbuf[i], lpt, 1 );
}
vector( cbuf, lpt, modi, 1 );
fftx( cbuf );
wor = bitrev( row, LOGP2Y );
putrow( cbuf, 2 * lpt, wor );
}
}
}