g01mt returns the value of the Landau density function ϕλ.

Syntax

C#
public static double g01mt(
	double x
)
Visual Basic
Public Shared Function g01mt ( _
	x As Double _
) As Double
Visual C++
public:
static double g01mt(
	double x
)
F#
static member g01mt : 
        x : float -> float 

Parameters

x
Type: System..::..Double
On entry: the argument λ of the function.

Return Value

g01mt returns the value of the Landau density function ϕλ.

Description

g01mt evaluates an approximation to the Landau density function ϕλ given by
ϕλ=12πic-ic+iexpλs+slnsds,
where c is an arbitrary real constant, using piecewise approximation by rational functions. Further details can be found in Kölbig and Schorr (1984).
To obtain the value of ϕλ, g01rt can be used.

References

Kölbig K S and Schorr B (1984) A program package for the Landau distribution Comp. Phys. Comm. 31 97–111

Error Indicators and Warnings

There are no failure exits from this routine.

Accuracy

At least 7 significant digits are usually correct, but occasionally only 6. Such accuracy is normally considered to be adequate for applications in experimental physics.
Because of the asymptotic behaviour of ϕλ, which is of the order of exp-exp-λ, underflow may occur on some machines when λ is moderately large and negative.

Parallelism and Performance

None.

Further Comments

None.

Example

This example evaluates ϕλ at λ=0.5, and prints the results.

Example program (C#): g01mte.cs

Example program data: g01mte.d

Example program results: g01mte.r

See Also