main()
{
int n1,n2,j;
float scale,sumz,sume;
for (n1=1,n2=npfa(n1+1); n2<NMAX; n1=n2,n2=npfa(n1+1)) {
for (j=0; j<n1*n2; j++)
c[j] = z[j] = cmplx(franuni(),franuni());
pfamcc(1,n1,n2,1,n1,z);
pfamcc(1,n2,n1,n1,1,z);
pfamcc(-1,n1,n2,1,n1,z);
pfamcc(-1,n2,n1,n1,1,z);
scale = 1.0/(float)(n1*n2);
for (j=0; j<n1*n2; j++)
z[j] = crmul(z[j],scale);
for (j=0,sumz=sume=0.0; j<n1*n2; j++) {
sumz += fcabs(z[j]);
sume += fcabs(csub(z[j],c[j]));
}
printf("n1 = %d n2 = %d sume/sumz = %0.10f\n",
n1,n2,sume/sumz);
if (sume/sumz>1.0e-6) printf("!!! warning !!!\n");
}
}
void
z_log(dcomplex *r, dcomplex *z)
{
r->dimag = atan2(z->dimag, z->dreal);
r->dreal = log( fcabs( z->dreal, z->dimag ) );
}
void
c_log(complex *r, complex *z)
{
r->imag = atan2(z->imag, z->real);
r->real = log( fcabs(z->real, z->imag) );
}
main()
{
int npoles,nfft,i;
float f3db,zero=0.0,fpass,apass,fstop,astop;
/*
printf("Enter npoles f3db:\n");
scanf("%d %f",&npoles,&f3db);
*/
printf("Enter fpass apass fstop astop:\n");
scanf("%f %f %f %f",&fpass,&apass,&fstop,&astop);
bfdesign(fpass,apass,fstop,astop,&npoles,&f3db);
printf("npoles = %d f3db = %f\n",npoles,f3db);
/* impulse response */
scopy(N,&zero,0,p,1);
p[0] = 1.0;
bflowpass(npoles,f3db,N,p,q);
pp1d(stdout,"impulse response",N,0,q);
/* amplitude spectrum */
nfft = npfa(N);
for (i=0; i<N; i++)
z[i] = cmplx(q[i],0.0);
for (i=N; i<nfft; i++)
z[i] = cmplx(0.0,0.0);
pfacc(1,nfft,z);
for (i=0; i<nfft; i++)
zamp[i] = fcabs(z[i]);
pp1d(stdout,"amplitude spectrum",nfft/2+1,0,zamp);
}
void
z_sqrt(dcomplex *r, dcomplex *z)
{
double mag;
if( (mag = fcabs(z->dreal, z->dimag)) == 0.)
r->dreal = r->dimag = 0.;
else if(z->dreal > 0) {
r->dreal = sqrt(0.5 * (mag + z->dreal) );
r->dimag = z->dimag / r->dreal / 2;
} else {
r->dimag = sqrt(0.5 * (mag - z->dreal) );
if(z->dimag < 0)
z->dimag = - z->dimag;
r->dreal = z->dimag / r->dimag / 2;
}
}
void
c_sqrt(complex *r, complex *z)
{
double mag;
if( (mag = fcabs(z->real, z->imag)) == 0.)
r->real = r->imag = 0.;
else if(z->real > 0) {
r->real = sqrt(0.5 * (mag + z->real) );
r->imag = z->imag / r->real / 2;
} else {
r->imag = sqrt(0.5 * (mag - z->real) );
if(z->imag < 0)
r->imag = - r->imag;
r->real = z->imag / r->imag /2;
}
}
double
z_abs(dcomplex *z)
{
return( fcabs( z->dreal, z->dimag ) );
}
float
c_abs(complex *z)
{
return( fcabs( z->real, z->imag ) );
}
main(int argc, char **argv)
{
int nt,nx; /* numbers of samples */
float dt,dx; /* sampling intervals */
float d1,d2; /* output intervals in F, K */
float f1,f2; /* output first samples in F, K */
int it,ix; /* sample indices */
int ntfft,nxfft; /* dimensions after padding for FFT */
int nF,nK; /* transform (output) dimensions */
int iF,iK; /* transform sample indices */
register complex **ct; /* complex FFT workspace */
register float **rt; /* float FFT workspace */
FILE *tracefp; /* temp file to hold traces */
/* Hook up getpar to handle the parameters */
initargs(argc,argv);
askdoc(1);
/* Get info from first trace */
if (!gettr(&intrace)) err("can't get first trace");
nt = intrace.ns;
/* dt is used only to set output header value d1 */
if (!getparfloat("dt", &dt)) {
if (intrace.dt) { /* is dt field set? */
dt = (float) intrace.dt / 1000000.0;
} else { /* dt not set, assume 4 ms */
dt = 0.004;
warn("tr.dt not set, assuming dt=0.004");
}
}
if (!getparfloat("dx",&dx)) {
if (intrace.d2) { /* is d2 field set? */
dx = intrace.d2;
} else {
dx = 1.0;
warn("tr.d2 not set, assuming d2=1.0");
}
}
/* Store traces in tmpfile while getting a count */
/*tracefp = etmpfile();*/
tracefp = etempfile(NULL);
nx = 0;
do {
++nx;
efwrite(intrace.data, FSIZE, nt, tracefp);
} while (gettr(&intrace));
/* Determine lengths for prime-factor FFTs */
ntfft = npfar(nt);
nxfft = npfa(nx);
if (ntfft >= MIN(SU_NFLTS, PFA_MAX)) err("Padded nt=%d--too big",ntfft);
if (nxfft >= MIN(SU_NFLTS, PFA_MAX)) err("Padded nx=%d--too big",nxfft);
/* Determine output header values */
d1 = 1.0/(ntfft*dt);
d2 = 1.0/(nxfft*dx);
f1 = 0.0;
f2 = -1.0/(2*dx);
/* Determine complex transform sizes */
nF = ntfft/2+1;
nK = nxfft;
/* Allocate space */
ct = alloc2complex(nF, nK);
rt = alloc2float(ntfft, nxfft);
/* Load traces into fft arrays and close tmpfile */
rewind(tracefp);
for (ix=0; ix<nx; ++ix) {
efread(rt[ix], FSIZE, nt, tracefp);
/* if ix odd, negate to center transform of dimension 2 */
if (ISODD(ix))
for (it=0; it<nt; ++it) rt[ix][it] = -rt[ix][it];
/* pad dimension 1 with zeros */
for (it=nt; it<ntfft; ++it) rt[ix][it] = 0.0;
}
efclose(tracefp);
/* Pad dimension 2 with zeros */
for (ix=nx; ix<nxfft; ++ix)
for (it=0; it<ntfft; ++it) rt[ix][it] = 0.0;
/* Fourier transform dimension 1 */
pfa2rc(1,1,ntfft,nx,rt[0],ct[0]);
/* Fourier transform dimension 2 */
pfa2cc(-1,2,nF,nxfft,ct[0]);
/* Compute and output amplitude spectrum */
for (iK=0; iK<nK; ++iK) {
for (iF=0; iF<nF; ++iF) outtrace.data[iF] = fcabs(ct[iK][iF]);
/* set header values */
outtrace.tracl = iK + 1;
outtrace.ns = nF;
outtrace.dt = 0; /* d1 is now the relevant step size */
outtrace.trid = KOMEGA;
outtrace.d1 = d1;
outtrace.f1 = f1;
outtrace.d2 = d2;
outtrace.f2 = f2;
puttr(&outtrace);
}
}
