Compute Hurst exponent from RMS-log2 transform

return_Hurst_exponent.c

// What we have computed are the fluctuations
// now we can retrieve the Hurst exponent via a polyfit again
float* log2_scales ;
// create a log2 x-axis
log2_scales = (float*)malloc(scales_len*sizeof(float));
for(int h=0; h<scales_len;h++){
  log2_scales[h]= Log2( (float)scales[h]);
}
// transform the RMS (fluctuations) with log2
float* log2_fluct ;
log2_fluct = (float*)malloc(scales_len*sizeof(float));
for(int h=0; h<scales_len;h++){
  log2_fluct[h]= Log2(rms[h]);
}
// Fit log2 x-axis with log2 fluctuations
polyfit(log2_scales,
        log2_fluct,
        scales_len,
        fitting_order,
        coeffs
      );
// return the RMS to fluct Cython memview
for (int h=0; h<scales_len;h++){
  fluct[h] = rms[h];
}
// Hurst exponent is coeffs[1]

// Free everything

free (tmpCoeff);
free(Xcumsum);
free(rms);
free(log2_fluct);
free(log2_scales);