functionLambertW

Closed approximation of Lambert's w function for solving f(x) = x exp(x) for x

Extends from Modelica.Icons.Function (Icon for functions).

Information

This function calculates an approximation of the inverse for

f(x) = y = x * exp( x )

within ∞ > y > -1/e. The relative deviation of this approximation for Lambert's w function x = W(y) is displayed in the following graph.

LambertW_deviation

For y > 10 and higher values the relative deviation is smaller 2%.

Inputs

TypeNameDefaultDescription
RealyInput f(x)

Outputs

TypeNameDefaultDescription
RealxOutput W(y)