approx_erf.h File Reference

#include "DataFormats/Math/interface/approx_exp.h"

Go to the source code of this file.

Functions
constexpr float	approx_erf (float x)

Function Documentation

constexpr float approx_erf

(

float

x

)

Definition at line 5 of file approx_erf.h.

References funct::abs(), validate-o2o-wbm::f, SiStripPI::min, and mathSSE::sqrt().

Referenced by SiTrivialInduceChargeOnStrips::induceVector().

                                    {
  auto xx = std::min(std::abs(x), 5.f);
  xx *= xx;
  return std::copysign(std::sqrt(1.f - unsafe_expf<4>(-xx * (1.f + 0.2733f / (1.f + 0.147f * xx)))), x);
  // return std::sqrt(1.f- std::exp(-x*x*(1.f+0.2733f/(1.f+0.147f*x*x)) ));
}