Lambert W function (Omega or Product Logarithm)

[james mcswiggenParticipant]

I would like to use non-liner curve fitting to fit the integrated Michaelis Menten equation to product vs time data. The function utilizes the Lambert W function (https://en.wikipedia.org/wiki/Lambert_W_function), which doesn’t appear to be part of DataGraph’s function list. First, am I correct in believing that the Lambert W function is absent from DataGraph? Second, can anyone recommend a workaround if that is the case? I tried fitting the inverse function, where product is treated as the independent variable and time is the dependent variable. That approach doesn’t require the Lambert W function, but while it worked for some of the model curves that I generated it didn’t work for all. Thus, I suspect I need to have the Lambert W function.

[dgteamModerator]

Hi James,

You are correct that we did not have the Lambert W function, so we are working on adding it now.  It will be in the next beta, likely out today or tomorrow.

In terms of using the inverse function, it sounds like sometimes it did work for you but not others?  Perhaps changing your initial guess would help as the non-linear fitting works best when you have a good initial guess.  In any case, we’ll let you know when we have the Lambert W function in the beta so you can try that out.

 

 

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