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fft and ifft as vector functions

pre-master-46
dwarning 13 years ago
committed by rlar
parent
0b1bff9fd8
commit
6a3da0105b
5 changed files with 262 additions and 3 deletions
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  1. 3
      src/frontend/evaluate.c
  2. 2
      src/frontend/parse.c
  3. 3
      src/include/ngspice/fteext.h
  4. 252
      src/maths/cmaths/cmath4.c
  5. 5
      src/maths/cmaths/cmath4.h

3
src/frontend/evaluate.c
View File

@ -859,7 +859,8 @@ apply_func_funcall(struct func *func, struct dvec *v, int *newlength, short int
/* Modified for passing necessary parameters to the derive function - A.Roldan */
if (eq(func->fu_name, "interpolate") || eq(func->fu_name, "deriv") || eq(func->fu_name, "group_delay")) /* Ack */
if (eq(func->fu_name, "interpolate") || eq(func->fu_name, "deriv") || eq(func->fu_name, "group_delay")
|| eq(func->fu_name, "fft") || eq(func->fu_name, "ifft")) /* Ack */
{
void * (*f) (void *data, short int type, int length,
int *newlength, short int *newtype,

2
src/frontend/parse.c
View File

@ -181,6 +181,8 @@ struct func ft_funcs[] = {
{ "vecd", cx_d },
{ "interpolate", (cx_function_t*) cx_interpolate },
{ "deriv", (cx_function_t*) cx_deriv },
{ "fft", (cx_function_t*) cx_fft },
{ "ifft", (cx_function_t*) cx_ifft },
{ "v", NULL },
{ NULL, NULL }
};

3
src/include/ngspice/fteext.h
View File

@ -118,7 +118,8 @@ extern void *cx_not(void *, short int , int , int *, short int *);
extern void *cx_interpolate(void *, short int , int , int *, short int *, struct plot *, struct plot *, int );
extern void *cx_deriv(void *, short int , int , int *, short int *, struct plot *, struct plot *, int );
extern void *cx_group_delay(void *, short int , int , int *, short int *, struct plot *, struct plot *, int );
extern void *cx_fft(void *, short int , int , int *, short int *, struct plot *, struct plot *, int );
extern void *cx_ifft(void *, short int , int , int *, short int *, struct plot *, struct plot *, int );
/* define.c */

252
src/maths/cmaths/cmath4.c
View File

@ -29,8 +29,10 @@ Author: 1985 Wayne A. Christopher, U. C. Berkeley CAD Group
#include "cmath4.h"
#include "ngspice/sim.h" /* To get SV_TIME */
#include "ngspice/fftext.h"
extern bool cx_degrees;
extern void vec_new(struct dvec *d);
void *
@ -498,3 +500,253 @@ cx_group_delay(void *data, short int type, int length, int *newlength, short int
return ((char *) group_delay);
}
void *
cx_fft(void *data, short int type, int length, int *newlength, short int *newtype, struct plot *pl, struct plot *newpl, int grouping)
{
int i, size, mm, fpts, order;
double span, scale, maxt;
double *indata;
double *time, *xscale, *win = NULL;
ngcomplex_t *outdata;
double *reald = NULL;
struct dvec *sv;
char window[BSIZE_SP];
if (grouping == 0)
grouping = length;
/* First do some sanity checks. */
if (!pl || !pl->pl_scale || !newpl || !newpl->pl_scale) {
fprintf(cp_err, "Internal error cx_fft: bad scale\n");
return (NULL);
}
if ((type != VF_REAL) && (type != VF_COMPLEX)) {
fprintf(cp_err, "Internal error cx_fft: argument has wrong data\n");
return (NULL);
}
/* size of fft input vector is power of two and larger than spice vector */
size = 1;
mm = 0;
while (size < length) {
size <<= 1;
mm++;
}
/* output vector has length of size/2 */
fpts = size/2;
*newlength = fpts;
*newtype = VF_COMPLEX;
indata = (double *) data;
outdata = alloc_c(fpts);
time = alloc_d(length);
xscale = TMALLOC(double, fpts);
if (pl->pl_scale->v_type == SV_TIME) { /* calculate the frequency from time */
span = pl->pl_scale->v_realdata[length-1] - pl->pl_scale->v_realdata[0];
for (i = 0; i<fpts; i++)
xscale[i] = i*1.0/span*length/size;
for (i = 0; i<length; i++)
time[i] = pl->pl_scale->v_realdata[i];
} else if (pl->pl_scale->v_type == SV_FREQUENCY) { /* take the frequency from ac data and calculate time */
/* Deal with complex frequency vector */
if (pl->pl_scale->v_type == VF_COMPLEX) {
span = realpart(pl->pl_scale->v_compdata[fpts-1]) - realpart(pl->pl_scale->v_compdata[0]);
for (i = 0; i<fpts; i++)
xscale[i] = realpart(pl->pl_scale->v_compdata[i]);
} else {
span = pl->pl_scale->v_realdata[fpts-1] - pl->pl_scale->v_realdata[0];
for (i = 0; i<fpts; i++)
xscale[i] = pl->pl_scale->v_realdata[i];
}
for (i = 0; i < length; i++)
time[i] = i*1.0/span*length/size;
span = time[length-1] - time[0];
} else {
fprintf(cp_err, "Internal error cx_fft: wrong analysis data\n");
return (NULL);
}
win = TMALLOC(double, length);
maxt = time[length-1];
if (!cp_getvar("specwindow", CP_STRING, window))
strcpy(window, "blackman");
if (!cp_getvar("specwindoworder", CP_NUM, &order))
order = 2;
if (order < 2)
order = 2;
if (fft_windows(window, win, time, length, maxt, span, order) == 0)
goto done;
/* create a new scale vector */
sv = alloc(struct dvec);
ZERO(sv, struct dvec);
sv->v_name = copy("fft_scale");
sv->v_type = SV_FREQUENCY;
sv->v_flags = (VF_REAL | VF_PERMANENT | VF_PRINT);
sv->v_length = fpts;
sv->v_realdata = xscale;
vec_new(sv);
printf("FFT: Time span: %g s, input length: %d, zero padding: %d\n", span, size, size-length);
printf("FFT: Freq. resolution: %g Hz, output length: %d\n", 1.0/span*length/size, fpts);
reald = TMALLOC(double, size);
for (i = 0; i < length; i++)
reald[i] = indata[i] * win[i];
for (i = length; i < size; i++)
reald[i] = 0.0;
fftInit(mm);
rffts(reald, mm, 1);
fftFree();
scale = size;
/* Re(x[0]), Re(x[N/2]), Re(x[1]), Im(x[1]), Re(x[2]), Im(x[2]), ... Re(x[N/2-1]), Im(x[N/2-1]). */
for (i = 0; i < fpts; i++) {
outdata[i].cx_real = reald[2*i]/scale;
outdata[i].cx_imag = reald[2*i+1]/scale;
}
done:
tfree(reald);
tfree(time);
tfree(win);
return ((void *) outdata);
}
void *
cx_ifft(void *data, short int type, int length, int *newlength, short int *newtype, struct plot *pl, struct plot *newpl, int grouping)
{
ngcomplex_t *indata = (ngcomplex_t *) data;
int i, size, mm, tpts, order;
double span, scale, maxt;
double *xscale, *win = NULL;
double *outdata;
double *reald = NULL;
struct dvec *sv;
char window[BSIZE_SP];
if (grouping == 0)
grouping = length;
/* First do some sanity checks. */
if (!pl || !pl->pl_scale || !newpl || !newpl->pl_scale) {
fprintf(cp_err, "Internal error cx_ifft: bad scale\n");
return (NULL);
}
if ((type != VF_REAL) && (type != VF_COMPLEX)) {
fprintf(cp_err, "Internal error cx_ifft: argument has wrong data\n");
return (NULL);
}
/* size of ifft input vector is power of two and larger than spice vector */
size = 1;
mm = 0;
while (size <= length) {
size <<= 1;
mm++;
}
/* output vector has same length as the plot scale vector */
tpts = pl->pl_scale->v_length;
*newlength = tpts;
*newtype = VF_REAL;
outdata = alloc_d(tpts);
xscale = TMALLOC(double, tpts);
if (pl->pl_scale->v_type == SV_TIME) { /* take the time from transient */
for (i = 0; i<tpts; i++)
xscale[i] = pl->pl_scale->v_realdata[i];
} else if (pl->pl_scale->v_type == SV_FREQUENCY) { /* calculate the time from frequency */
/* Deal with complex frequency vector */
if (pl->pl_scale->v_type == VF_COMPLEX)
span = realpart(pl->pl_scale->v_compdata[tpts-1]) - realpart(pl->pl_scale->v_compdata[0]);
else
span = pl->pl_scale->v_realdata[tpts-1] - pl->pl_scale->v_realdata[0];
for (i = 0; i<tpts; i++)
xscale[i] = i*1.0/span*length/size;
} else {
fprintf(cp_err, "Internal error cx_ifft: wrong analysis data\n");
return (NULL);
}
span = xscale[tpts-1] - xscale[0];
/* create a new scale vector */
sv = alloc(struct dvec);
ZERO(sv, struct dvec);
sv->v_name = copy("ifft_scale");
sv->v_type = SV_TIME;
sv->v_flags = (VF_REAL | VF_PERMANENT | VF_PRINT);
sv->v_length = tpts;
sv->v_realdata = xscale;
vec_new(sv);
win = TMALLOC(double, tpts);
maxt = xscale[tpts-1];
if (!cp_getvar("specwindow", CP_STRING, window))
strcpy(window, "blackman");
if (!cp_getvar("specwindoworder", CP_NUM, &order))
order = 2;
if (order < 2)
order = 2;
if (fft_windows(window, win, xscale, tpts, maxt, span, order) == 0)
goto done;
printf("IFFT: Time span: %g s, output length: %d\n", span, tpts);
printf("IFFT: Freq. resolution: %g Hz, input length: %d\n", 1.0/span*tpts/(2*length), length);
reald = TMALLOC(double, 2*size);
/* Re(x[0]), Re(x[N/2]), Re(x[1]), Im(x[1]), Re(x[2]), Im(x[2]), ... Re(x[N/2-1]), Im(x[N/2-1]). */
for (i = 0; i < length; i++) {
reald[2*i] = indata[i].cx_real;
reald[2*i+1] = indata[i].cx_imag;
}
for (i = length; i < size; i++) {
reald[2*i] = 0.0;
reald[2*i+1] = 0.0;
}
fftInit(mm);
riffts(reald, mm, 1);
fftFree();
scale = 2*length;
for (i = 0; i < tpts; i++)
outdata[i] = reald[i] * scale/win[i];
done:
tfree(reald);
tfree(win);
return ((void *) outdata);
}

5
src/maths/cmaths/cmath4.h
View File

@ -15,6 +15,9 @@ void * cx_deriv(void *data, short int type, int length, int *newlength, short in
struct plot *pl, struct plot *newpl, int grouping);
void * cx_group_delay(void *data, short int type, int length, int *newlength, short int *newtype,
struct plot *pl, struct plot *newpl, int grouping);
void * cx_fft(void *data, short int type, int length, int *newlength, short int *newtype,
struct plot *pl, struct plot *newpl, int grouping);
void * cx_ifft(void *data, short int type, int length, int *newlength, short int *newtype,
struct plot *pl, struct plot *newpl, int grouping);
#endif
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