linear_phase_fir_kernel_to_minimum_phase_whitening_fir_kernel():

- remove superfluous array slice operations
- future-proof integer divisions
- "inline" some algebra to reduce swig interaction overhead

gstlal/python/reference_psd.py

@@ -533,15 +533,14 @@ class PSDFirKernel(object):
 		)
 
 		lal.COMPLEX16TimeFreqFFT(absX, kernel_tseries, self.fwdplan)
-		absX.data.data[:] = numpy.roll(abs(absX.data.data), -working_length / 2 + 1)[:] * sample_rate
+		absX.data.data[:] = numpy.roll(abs(absX.data.data), -working_length // 2 + 1) * sample_rate
 
 		#
 		# compute the cepstrum of the kernel
 		# (i.e., the iFFT of the log of the abs of the FFT of the kernel)
 		#
 
-		logabsX.data.data = numpy.log(absX.data.data)
-		logabsX.data.data[:] = numpy.roll(logabsX.data.data, +working_length / 2 + 1)[:]
+		logabsX.data.data[:] = numpy.roll(numpy.log(absX.data.data), +working_length // 2 + 1)
 		lal.COMPLEX16FreqTimeFFT(cepstrum, logabsX, self.revplan)
 		cepstrum.data.data /= sample_rate
 
@@ -551,26 +550,25 @@ class PSDFirKernel(object):
 
 		sgn = scipy.ones(working_length)
 		sgn[0] = 0.
-		sgn[(len(sgn)+1)/2] = 0.
-		sgn[(len(sgn)+1)/2:] *= -1
+		sgn[(len(sgn) + 1) // 2] = 0.
+		sgn[(len(sgn) + 1) // 2:] *= -1
 		cepstrum.data.data *= sgn
 
 		#
 		# compute theta
 		#
+
 		lal.COMPLEX16TimeFreqFFT(theta, cepstrum, self.fwdplan)
-		theta.data.data *= -1.j
-		theta.data.data[:] = numpy.roll(theta.data.data, -working_length / 2)[:] * sample_rate
+		theta.data.data[:] = numpy.roll(-1.j * theta.data.data, -working_length // 2) * sample_rate
 
 		#
 		# compute minimum phase kernel
 		#
 
-		absX.data.data[:]  = absX.data.data * scipy.exp(1.j * theta.data.data)[:]
-		absX.data.data[:] = numpy.roll(absX.data.data, +working_length / 2 + 1)[:] / sample_rate
+		absX.data.data[:] = numpy.roll(absX.data.data * scipy.exp(1.j * theta.data.data), +working_length // 2 + 1) / sample_rate
 		lal.COMPLEX16FreqTimeFFT(min_phase_kernel, absX, self.revplan)
 
-		kernel = numpy.real(min_phase_kernel.data.data)
+		kernel = min_phase_kernel.data.data.real
 
 		#
 		# this kernel needs to be reversed to follow conventions used with the