Source code for sasmodels.gengauss

#!/usr/bin/env python
Generate the Gauss-Legendre integration points and save them as a C file.
from __future__ import division, print_function

import numpy as np
from numpy.polynomial.legendre import leggauss

[docs]def gengauss(n, path): """ Save the Gauss-Legendre integration points for length *n* into file *path*. """ z, w = leggauss(n) # Make sure array size is a multiple of 4 if n%4: array_size = n + (4 - n%4) z, w = [np.hstack((v, [0.]*(4-n%4))) for v in (z, w)] else: array_size = n with open(path, "w") as fid: fid.write("""\ // Generated by sasmodels.gengauss.gengauss(%d) #ifdef GAUSS_N # undef GAUSS_N # undef GAUSS_Z # undef GAUSS_W #endif #define GAUSS_N %d #define GAUSS_Z Gauss%dZ #define GAUSS_W Gauss%dWt """%(n, n, n, n)) if array_size != n: fid.write("// Note: using array size %d so that it is a multiple of 4\n\n"%array_size) fid.write("constant double Gauss%dWt[%d]={\n"%(n, array_size)) fid.write(",\n".join("\t% .15e"%v for v in w)) fid.write("\n};\n") fid.write("constant double Gauss%dZ[%d]={\n"%(n, array_size)) fid.write(",\n".join("\t% .15e"%v for v in z)) fid.write("\n};")