lambert W equation ,h

[ajit107]

I am trying to solve some Transcendental equation using LabVIEW by using Lambert W function,is anyone have an idea how to create VI of Lambert W function

[alexderjuengere]

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@ajit107 wrote:

I am trying to solve some Transcendental equation 

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 So you need the LametW function as some kind of LUT (e.g. Solving_equations)

How does your transcendental equation look like?

According to wikipedia, the Lambert W function for  real numbers can be expressed as:

I suppose, this can be extended to complex numbers.

Note that the Formula Node in the above snippet doesn't support complex numbers.

[altenbach]

Here is a slightly simpler implementation of the REAL function, but I am pretty sure you are looking for the complex version. (I am just using complex to define x and y for the xy graph. Not the same)

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@ajit107 wrote:

I am trying to solve some Transcendental equation using LabVIEW by using Lambert W function,is anyone have an idea how to create VI of Lambert W function

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Please described exactly what you mean by "solve". What are the inputs (e.g. with inputs z(complex) and k(integer), for example) and what is the desired output.

[Martin_Henz]

you can

- use Newton Raphson Zero Finder or the Ridders Zero Finder.

- programm the recursive newton-raphson algorithm using the formula

- use the following formula for large x values

W= ln(x)-ln(ln(x))+ln(ln(x))/ln(x)

[ajit107]

i have the value of the x in the  order 125e110, which will be a suitable algorithm or vi for lambert w function please suggest 

[altenbach]

That's a pretty large x. Have you tried the approximation for large x values mentioned above?

[Martin_Henz]

For 125E110 the NR Zero Finder result is 2,525809422E+2 and the reverse calulation is 125E110.