On the very accurate evaluation of the Voigt/complex error function with small imaginary argument

Abstract

A rapidly convergent series, based on Taylor expansion of the imaginary part of the complex error function, is presented for highly accurate approximation of the Voigt/complex error function with small imaginary argument (Y less than 0.1). Error analysis and run-time tests in double-precision computing platform reveals that in the real and imaginary parts the proposed algorithm provides average accuracy exceeding 10^-15 and 10^-16, respectively, and the calculation speed is as fast as that of reported in recent publications. An optimized MATLAB code providing rapid computation with high accuracy is presented.