"""Definitions for the `Viscous` class."""
import numpy as np
from scipy.interpolate import interp1d
from mosfit.modules.transforms.transform import Transform
CLASS_NAME = 'Viscous'
[docs]class Viscous(Transform):
"""Viscous delay transform."""
N_INT_TIMES = 1000
MIN_LOG_SPACING = -3
[docs] def process(self, **kwargs):
"""Process module."""
Transform.process(self, **kwargs)
tvisc = kwargs['Tviscous']
new_lums = np.zeros_like(self._times_to_process)
if len(self._dense_times_since_exp) < 2:
return {self.dense_key('luminosities'): new_lums}
min_te = min(self._dense_times_since_exp)
tb = max(0.0, min_te)
linterp = interp1d(
self._dense_times_since_exp, self._dense_luminosities, copy=False,
assume_sorted=True)
uniq_times = np.unique(self._times_to_process[
(self._times_to_process >= tb) & (
self._times_to_process <= self._dense_times_since_exp[-1])])
lu = len(uniq_times)
num = int(self.N_INT_TIMES / 2.0)
lsp = np.logspace(
np.log10(tvisc /
self._dense_times_since_exp[-1]) +
self.MIN_LOG_SPACING, 0, num)
xm = np.unique(np.concatenate((lsp, 1 - lsp)))
int_times = np.clip(tb + (uniq_times.reshape(lu, 1) - tb) * xm, tb,
self._dense_times_since_exp[-1])
int_tes = int_times[:, -1]
int_lums = linterp(int_times)
int_args = int_lums * np.exp(
(int_times - int_tes.reshape(lu, 1)) / tvisc)
int_args[np.isnan(int_args)] = 0.0
uniq_lums = np.trapz(int_args, int_times) / tvisc
new_lums = uniq_lums[np.searchsorted(uniq_times,
self._times_to_process)]
return {self.dense_key('luminosities'): new_lums}