1 files changed, 0 insertions, 101 deletions
diff --git a/src/nd-random.c b/src/nd-random.c
deleted file mode 100644
index 25abc7a..0000000
--- a/src/nd-random.c
+++ /dev/null
@@ -1,101 +0,0 @@
-#include <float.h>
-#include <math.h>
-#include <gsl/gsl_blas.h>
-#include <gsl/gsl_randist.h>
-#include <gsl/gsl_sf_gamma.h>
-#include "nd-random.h"
-#include "utils.h"
-
-static double beta_inc_unnormalized (double a, double b, double x);
-static double incomplete_wallis_integral (double theta, unsigned int m);
-
-void random_direction_vector (const gsl_rng* r, gsl_vector* x)
-{
-  gsl_ran_dir_nd(r, x->size, x->data);
-}
-
-static void rotate_from_nth_canonical (gsl_vector* x, const gsl_vector* orient)
-{
-  const size_t n = x->size;
-  double xn = gsl_vector_get(x, n - 1);
-  double mun = gsl_vector_get(orient, n - 1);
-  gsl_vector_const_view orient_sub = gsl_vector_const_subvector(orient, 0, n - 1);
-  double b = gsl_blas_dnrm2(&orient_sub.vector);
-  double a = (dot_product(orient, x) - xn*mun) / b;
-  double c = mun, s = sqrt(1 - gsl_pow_2(c));
-  gsl_blas_daxpy((xn*s + a*(c - 1))/b, orient, x);
-  gsl_vector_set(x, n - 1, gsl_vector_get(x, n - 1)
-                 + xn*(c - 1) - a*s
-                 - mun*(xn*s + a*(c - 1))/b);
-}
-
-/* TODO: There is an edge case when mean is the (n-1)th canonical
-   basis vector. Fix it.
-*/
-void hollow_cone_random_vector (const gsl_rng* r, const gsl_vector* mean, double theta_min, double theta_max, gsl_vector* x)
-{
-  unsigned int n = x->size;
-  gsl_ran_dir_nd(r, n - 1, x->data);
-
-  // Generate random vector around the nth canonical basis vector
-  double omega_min = planar_angle_to_solid_angle(theta_min, n);
-  double omega_max = planar_angle_to_solid_angle(theta_max, n);
-  gsl_vector_scale(x, cos(theta_max) * tan(solid_angle_to_planar_angle(gsl_ran_flat(r, omega_min, omega_max), n)));
-  gsl_vector_set(x, n - 1, cos(theta_max));
-  gsl_vector_scale(x, 1.0/gsl_blas_dnrm2(x));
-
-  // Rotate to arbitrary basis
-  rotate_from_nth_canonical(x, mean);
-}
-
-void subsampling_random_vector (const gsl_rng* r, const gsl_vector* mean, double theta_max, gsl_vector* x)
-{
-  hollow_cone_random_vector(r, mean, 0, theta_max, x);
-}
-
-static double beta_inc_unnormalized (double a, double b, double x)
-{
-  return gsl_sf_beta_inc(a, b, x) * gsl_sf_beta(a, b);
-}
-
-static double incomplete_wallis_integral (double theta, unsigned int m)
-{
-  /**
-     @param theta 0 < theta < pi
-     @param m
-     @return \int_0^\theta \sin^m x dx
-   **/
-  if ((theta < 0) || (theta > M_PI))
-    GSL_ERROR("Incomplete Wallis integral only allows theta in [0,pi]", GSL_EDOM);
-  if (theta < M_PI_2)
-    return 0.5 * beta_inc_unnormalized((m+1)/2.0, 0.5, gsl_pow_2(sin(theta)));
-  else
-    return 0.5 * (gsl_sf_beta((m+1)/2.0, 0.5) + beta_inc_unnormalized(0.5, (m+1)/2.0, gsl_pow_2(cos(theta))));
-}
-
-double planar_angle_to_solid_angle (double planar_angle, unsigned int dimension)
-{
-  return 2 * pow(M_PI, (dimension - 1)/2.0)
-    * incomplete_wallis_integral(planar_angle, dimension - 2)
-    / gsl_sf_gamma((dimension - 1)/2.0);
-}
-
-double solid_angle_to_planar_angle (double solid_angle, unsigned int dimension)
-{
-  double f (double planar_angle, void* params)
-  {
-    return planar_angle_to_solid_angle(planar_angle, dimension) - solid_angle;
-  }
-
-  gsl_function gsl_f = {&f};
-  /* if (fabs(GSL_FN_EVAL(&gsl_f, 0))/surface_area_of_ball(dimension) < BISECTION_FUNCTION_EPSABS) */
-  /*   return 0; */
-  /* else if (fabs(GSL_FN_EVAL(&gsl_f, M_PI))/surface_area_of_ball(dimension) < BISECTION_FUNCTION_EPSABS) */
-  /*   return M_PI; */
-  /* else return bisection(&gsl_f, 0, M_PI); */
-  if (solid_angle == 0)
-    return 0;
-  else if (solid_angle == surface_area_of_ball(dimension))
-    return M_PI;
-  else return bisection(&gsl_f, 0, M_PI);
-}