Charles
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 Apr 25 accepted Checking if input is a function Apr 25 comment Checking if input is a function @J.M. That's interesting -- is there a way to convert an anonymous function to this form automatically? Apr 25 asked Checking if input is a function Jan 4 awarded Notable Question Jul 30 comment Substitute a function's definition for its name @Guesswhoitis.: Can you explain how to do this? I recognized the (potential) problem of clashing variables but don't know how to handle this in Mathematica. (I can handle it in other languages, but my Math'ca isn't so good yet.) Jul 30 accepted Substitute a function's definition for its name Jul 30 asked Substitute a function's definition for its name Dec 4 comment Inverse of LogIntegral Works great, thanks! I tweaked the WorkingPrecision and PrecisionGoal upward and all was good. Dec 4 accepted Inverse of LogIntegral Dec 4 comment Inverse of LogIntegral @DanielLichtblau: Thanks. (Maybe that should be an answer.) Mathematica is still giving me answers I don't believe (say, integrating up to 10^200 giving an answer of 2*10^7 instead of < 0.1) but at this point it seems hopeless. At least it works for small numbers. Dec 4 comment Inverse of LogIntegral (The true answer should be about 0.01125, or 19 orders of magnitude smaller.) Dec 4 comment Inverse of LogIntegral @DanielLichtblau: That's not a sensible answer, though. The li^{-1}(x) > x (in fact ~ x log x), so the integral should be less than the integral of 1/x over the same region, which is about 4.6. Dec 4 comment Inverse of LogIntegral @Artes: With an NIntegrate::inumr error. I've edited in code. Dec 4 revised Inverse of LogIntegral expand, as requested Dec 4 asked Inverse of LogIntegral Aug 5 comment Use of Strassen's algorithm @TysonWilliams: BLAS does use Strassen in DGEMMS*. But Daniel's description of why to avoid that algorithm for floating-point calculations is apt. Jul 2 awarded Curious May 28 awarded Nice Question May 22 comment How do I get Mathematica to return a function call unevaluated? Hah! So at least I wasn't too far off the mark, just careless. Thanks for pointing this out! May 22 awarded Yearling