21,066 reputation
42568
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location Ann Arbor, MI
age 77
visits member for 2 years, 1 month
seen 2 days ago

I am a retired software developer. I retired at the end of 2003 and since then my computer programming activities have been for recreational purposes. I find Mathematica excellent for that.

I started using Mathematica in 1997 (Ver. 3). I am currently using Ver. 9. Although I have used Mathematica for all kinds of stuff, I use it mostly to pursue my long standing interest in Euclidean geometry, both in its classical Greek synthetic form and in its more modern analytical/transformational form.


Aug
27
revised Power::infy: error using FindFit
Middling clean-up
Aug
27
revised How to solve three equations with four unknowns iteratively?
Improved formatting
Aug
27
comment How to do DateDifference on table items containing dates
@Elisa. I am using V10. Earlier versions of Mathematica didn't require QuantityMagnitude to get a numeric result.
Aug
26
revised How to do DateDifference on table items containing dates
edited tags; edited title
Aug
26
answered How to do DateDifference on table items containing dates
Aug
26
awarded  Nice Question
Aug
26
comment Can I check if an expression is positive using assumptions?
To set global assumptions, use $Assumptions = {{c1, c2, λ, μ} > 0, Element[{c1, c2, λ, μ}, Reals], μ > λ}.
Aug
26
revised Can I check if an expression is positive using assumptions?
Improved formatting
Aug
26
reviewed No Action Needed Can I check if an expression is positive using assumptions?
Aug
26
revised How to make Epilog render behind the main plot
deleted 11 characters in body; edited title
Aug
26
comment How to make Epilog render behind the main plot
Use Prolog, not Epilog.
Aug
25
comment Counting the zeros in a factorial expansion
Let us note for the record that Count[IntegerDigits[1000!], 0] gives the result 472, essentially instantaneously.
Aug
25
reviewed Reviewed Counting the zeros in a factorial expansion
Aug
25
revised Counting the zeros in a factorial expansion
deleted 21 characters in body; edited tags; edited title
Aug
25
revised What is my problem with MeshFunction?
added remarks about chop tolerance
Aug
25
comment What is my problem with MeshFunction?
@MichaelE2. It is easier and more efficient to loosen the chop tolerance. Boole[Chop[Cos[#1], .01] == 0 && #2 > 0] & works fine of the domain {x, 0, N[15 Pi]} without increasing PlotPoints.
Aug
25
revised What is my problem with MeshFunction?
added 7 characters in body
Aug
25
comment What is my problem with MeshFunction?
@MichaelE2. Do you think the multiplicity invalidates my answer?
Aug
25
comment Compiler stack overflow
Make your "huge function" smaller? Perhaps by breaking in to several sub-functions that can compiled separately.
Aug
25
revised Compiler stack overflow
Improved formatting