Source code for the computation of the benchmark metric: Circular Variance

float circular_variance_tuning_curve(r,theta,n,theta_max)
     float *r;         // response amplitude [n]
     float *theta;     // angle 0..theta_max (deg) [n]
     int n;            // number of data points
     float theta_max;  // e.g., 360.0 for dir, 180.0 for ori
{
  int i;
  float tot,x,y,cv,tm2pi;

  tm2pi = 2.0 * M_PI / theta_max;

  tot = x = y = 0.0;
  for(i=0;i<n;i++){
    tot += amp[i];
    x += amp[i] * cos(tm2pi * theta[i]);
    y += amp[i] * sin(tm2pi * theta[i]);
  }
  cv = 1.0 - sqrt(x*x + y*y) / tot;

  return cv;
}