EVOLUTION-MANAGER

Edit File: vonmises.py

from __future__ import division, print_function, absolute_import import numpy as np import scipy.stats from scipy.special import i0 def von_mises_cdf_series(k,x,p): x = float(x) s = np.sin(x) c = np.cos(x) sn = np.sin(p*x) cn = np.cos(p*x) R = 0 V = 0 for n in range(p-1,0,-1): sn, cn = sn*c - cn*s, cn*c + sn*s R = 1./(2*n/k + R) V = R*(sn/n+V) return 0.5+x/(2*np.pi) + V/np.pi def von_mises_cdf_normalapprox(k, x): b = np.sqrt(2/np.pi)*np.exp(k)/i0(k) z = b*np.sin(x/2.) return scipy.stats.norm.cdf(z) def von_mises_cdf(k,x): ix = 2*np.pi*np.round(x/(2*np.pi)) x = x-ix k = float(k) # These values should give 12 decimal digits CK = 50 a = [28., 0.5, 100., 5.0] if k < CK: p = int(np.ceil(a[0]+a[1]*k-a[2]/(k+a[3]))) F = np.clip(von_mises_cdf_series(k,x,p),0,1) else: F = von_mises_cdf_normalapprox(k, x) return F+ix