NAG FL Interface
g01etf returns the value of the Landau distribution function .
|Real (Kind=nag_wp), Intent (In)
|C Header Interface
g01etf_ (const double *x)
The routine may be called by the names g01etf or nagf_stat_prob_landau.
evaluates an approximation to the Landau distribution function
is described in g01mtf
, using piecewise approximation by rational functions. Further details can be found in Kölbig and Schorr (1984)
Kölbig K S and Schorr B (1984) A program package for the Landau distribution Comp. Phys. Comm. 31 97–111
– Real (Kind=nag_wp)
On entry: the argument of the function.
Error Indicators and Warnings
At least significant digits are usually correct, but occasionally only . Such accuracy is normally considered to be adequate for applications in experimental physics.
Because of the asymptotic behaviour of , which is of the order of , underflow may occur on some machines when is moderately large and negative.
Parallelism and Performance
Background information to multithreading can be found in the Multithreading
g01etf is not threaded in any implementation.
This example evaluates at , and prints the results.