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surfacethought
Level III

I know this is a bit of a stretch, but is there anyway to encode the Ei(x) function in JMP.

     The Ei(X) function is (I guess) a fairly rare function. At least I've never had to deal with it before. But it has popped up in an analysis I am doing, I am wondering if there is anyway to encode it        into a formula in JMP. Clearly, it isn't in there by default, but is there a way to manually enter this:

 \mbox{Ei}(x)=\int_{-\infty}^x\frac{e^t}t\,dt.\,
Into a formula column? Thanks in advance.
--SurfaceThought
13 REPLIES 13
pmroz
Super User

Re: I know this is a bit of a stretch, but is there anyway to encode the Ei(x) function in JMP.

They're pretty much completely different languages.  If I have some free time (hah) I'll take a stab at converting it. 

stevedenham
Level II

Re: I know this is a bit of a stretch, but is there anyway to encode the Ei(x) function in JMP.

I think there is an R package that will do the integration.  Would that be easier to implement than re-coding?

Steve Denham

pmroz
Super User

Re: I know this is a bit of a stretch, but is there anyway to encode the Ei(x) function in JMP.

OK here's a JSL implementation of the Fortran code.  The code runs, but you'll need to test it out to make sure the numbers are good.  It's pretty much a straight conversion of the Fortran program.  Interesting exercise!

surfacethought
Level III

Re: I know this is a bit of a stretch, but is there anyway to encode the Ei(x) function in JMP.

PMroz,

This is incredible! It works flawlessly! This is certainly beer-worthy work, if you think of a way I can buy you one let me know

--SurfaceThought