/**
* gwy_spectra_set_spectrum:
* @spectra: A spectra object.
* @i: Index of a spectrum to replace
* @new_spectrum: A #GwyDataLine Object containing the new spectrum.
*
* Replaces the ith spectrum in the spectra object with a the
* supplied spectrum, new_spectrum. It takes its own reference
* to the New_Spectrum dataline.
*
* Since: 2.7
**/
void
gwy_spectra_set_spectrum(GwySpectra *spectra,
guint i,
GwyDataLine *new_spectrum)
{
GwySpectrum *spec;
g_return_if_fail(GWY_IS_SPECTRA(spectra));
g_return_if_fail(GWY_IS_DATA_LINE(new_spectrum));
g_return_if_fail(i < spectra->spectra->len);
spec = &g_array_index(spectra->spectra, GwySpectrum, i);
g_object_ref(new_spectrum);
g_object_unref(spec->ydata);
spec->ydata = new_spectrum;
}
/**
* gwy_spectra_add_spectrum:
* @spectra: A spectra object.
* @new_spectrum: A GwyDataLine containing the spectrum to append.
* @x: The physical x coordinate of the location of the spectrum.
* @y: The physical y coordinate of the location of the spectrum.
*
* Appends a new_spectrum to the spectra collection with a position of x, y.
* gwy_spectra_add takes a refference to the supplied spectrum.
*
* Since: 2.7
**/
void
gwy_spectra_add_spectrum(GwySpectra *spectra,
GwyDataLine *new_spectrum,
gdouble x, gdouble y)
{
GwySpectrum spec;
g_return_if_fail(GWY_IS_SPECTRA(spectra));
g_return_if_fail(GWY_IS_DATA_LINE(new_spectrum));
g_object_ref(new_spectrum);
spec.x = x;
spec.y = y;
spec.ydata = new_spectrum;
spec.selected = FALSE;
g_array_append_val(spectra->spectra, spec);
}
/**
* gwy_data_line_psdf:
* @data_line: data line
* @target_line: result data line
* @windowing: windowing method
* @interpolation: interpolation method
*
* Copmutes power spectral density function and stores the values in
* @target_line.
**/
void
gwy_data_line_psdf(GwyDataLine *data_line, GwyDataLine *target_line, gint windowing, gint interpolation)
{
GwyDataLine *iin, *rout, *iout;
gint i, order, newres, oldres;
g_return_if_fail(GWY_IS_DATA_LINE(data_line));
oldres = data_line->res;
order = (gint) floor(log ((gdouble)data_line->res)/log (2.0)+0.5);
newres = (gint) pow(2,order);
iin = (GwyDataLine *)gwy_data_line_new(newres, data_line->real, TRUE);
rout = (GwyDataLine *)gwy_data_line_new(newres, data_line->real, TRUE);
iout = (GwyDataLine *)gwy_data_line_new(newres, data_line->real, TRUE);
/*resample to 2^N (this could be done within FFT, but with loss of precision)*/
gwy_data_line_resample(data_line, newres, interpolation);
gwy_data_line_fft(data_line, iin, rout, iout, gwy_data_line_fft_hum,
windowing, 1, interpolation,
TRUE, TRUE);
gwy_data_line_resample(target_line, newres/2.0, GWY_INTERPOLATION_NONE);
/*compute module*/
for (i = 0; i < (newres/2); i++) {
target_line->data[i] = (rout->data[i]*rout->data[i] + iout->data[i]*iout->data[i])
*data_line->real/(newres*newres*2*G_PI);
}
target_line->real = 2*G_PI*target_line->res/data_line->real;
/*resample to given output size*/
gwy_data_line_resample(target_line, oldres/2.0, interpolation);
g_object_unref(rout);
g_object_unref(iin);
g_object_unref(iout);
}