.BuildSysPro.IBPSA.Utilities.Math.Functions.exponentialIntegralE1

Information

Evaluates the exponential integral (E₁), based on the polynomial and rational approximations of Abramowitz and Stegun (1964).

References

Abramowitz, Milton, and Irene A. Stegun. Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables. National Bureau of Standards. (1964): 1046 p.

Interface

function exponentialIntegralE1
  extends Modelica.Icons.Function;
  input Real x "Independent variable";
  output Real E1 "Exponential integral E1(x)";
end exponentialIntegralE1;

Revisions

• July 16, 2018 by Michael Wetter:
  Inlined function.
• March 21, 2018 by Massimo Cimmino:
  First implementation.