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com_psd(), reuse the window function `fft_windows()'

This commit is contained in:
dwarning 2013-08-27 14:39:04 +02:00 committed by rlar
parent fe01e537cd
commit 845dd554e2
1 changed files with 12 additions and 89 deletions
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101
src/frontend/com_fft.c
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@ -224,12 +224,13 @@ com_psd(wordlist *wl)
char *s;
struct dvec *f, *vlist, *lv = NULL, *vec;
struct pnode *pn, *names = NULL;
char window[BSIZE_SP];
double maxt;
double *reald = NULL, *imagd = NULL;
int sign;
double scaling, sum;
int order;
double scale, sigma;
if (!plot_cur || !plot_cur->pl_scale) {
fprintf(cp_err, "Error: no vectors loaded.\n");
@ -268,95 +269,17 @@ com_psd(wordlist *wl)
// output vector has length of size/2
fpts = size>>1;
// window function
win = TMALLOC(double, tlen);
{
char window[BSIZE_SP];
double maxt = time[tlen-1];
if (!cp_getvar("specwindow", CP_STRING, window))
strcpy(window, "blackman");
if (eq(window, "none"))
for (i = 0; i < tlen; i++)
win[i] = 1;
else if (eq(window, "rectangular"))
for (i = 0; i < tlen; i++) {
if (maxt-time[i] > span)
win[i] = 0;
else
win[i] = 1;
}
else if (eq(window, "hanning") || eq(window, "cosine"))
for (i = 0; i < tlen; i++) {
if (maxt-time[i] > span)
win[i] = 0;
else
win[i] = 1 - cos(2*M_PI*(time[i]-maxt)/span);
}
else if (eq(window, "hamming"))
for (i = 0; i < tlen; i++) {
if (maxt-time[i] > span)
win[i] = 0;
else
win[i] = 1 - 0.92/1.08*cos(2*M_PI*(time[i]-maxt)/span);
}
else if (eq(window, "triangle") || eq(window, "bartlet"))
for (i = 0; i < tlen; i++) {
if (maxt-time[i] > span)
win[i] = 0;
else
win[i] = 2 - fabs(2+4*(time[i]-maxt)/span);
}
else if (eq(window, "blackman")) {
int order;
if (!cp_getvar("specwindoworder", CP_NUM, &order))
order = 2;
if (order < 2)
order = 2; /* only order 2 supported here */
for (i = 0; i < tlen; i++) {
if (maxt-time[i] > span) {
win[i] = 0;
} else {
win[i] = 1;
win[i] -= 0.50/0.42*cos(2*M_PI*(time[i]-maxt)/span);
win[i] += 0.08/0.42*cos(4*M_PI*(time[i]-maxt)/span);
}
}
} else if (eq(window, "gaussian")) {
if (!cp_getvar("specwindoworder", CP_NUM, &order))
order = 2;
if (order < 2)
order = 2;
sigma = 1.0/order;
scale = 0.83/sigma;
for (i = 0; i < tlen; i++) {
if (maxt-time[i] > span)
win[i] = 0;
else
win[i] = scale*exp(-0.5 * pow((time[i]-maxt/2)/(sigma*maxt/2), 2));
}
/*
* int order;
* double scale;
* extern double erfc(double);
* if (!cp_getvar("specwindoworder", CP_NUM, &order))
* order = 2;
* if (order < 2)
* order = 2;
* scale = pow(2*M_PI/order, 0.5)*(0.5-erfc(pow(order, 0.5)));
* for (i = 0; i < tlen; i++) {
* if (maxt-time[i] > span) {
* win[i] = 0;
* } else {
* win[i] = exp(-0.5*order*(1-2*(maxt-time[i])/span)
* *(1-2*(maxt-time[i])/span))/scale;
* }
* }
*/
} else {
fprintf(cp_err, "Warning: unknown window type %s\n", window);
goto done;
}
}
maxt = time[tlen-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, tlen, maxt, span, order) == 0)
goto done;
names = ft_getpnames(wl, TRUE);
vlist = NULL;