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location Ann Arbor, MI
age 77
visits member for 2 years, 2 months
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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.


Dec
19
comment My algorithm produces too many permutations
This question appears to be off-topic because it is too localized; i.e, it applies only to the local situation and needs of its poster and answers will not benefit others.
Dec
9
comment What are the most common pitfalls awaiting new users?
@rcollyer. I think what you suspect is very likely the case. It certainly seems entirely reasonable to me.
Dec
6
comment Unexpected result from StringReplace
@SjoerdC.deVries. Your 1st comment would certainly explain my result. Checking the documentation once more, all the examples I can find of Except used in string operations support your assertion. Can you point me to anywhere it is explicitly documented? Your 2nd comment can be applied not only to this toy problem, but to my real problem as well. If you write it up I will up-vote it and accept it.
Nov
15
comment Want a different color for each curve displayed with Show
Duplicate of this question?
Nov
11
comment Equation is solved quickly using Solve but takes too long using NSolve
Find root works works well for this equation. FindRoot[(1. - (2.25577*^-5) h)^5.2558 == 0.9644952131579817, {h, 300}] returns {h -> 303.869} essentially instantaneously.
Nov
10
comment How to exclude some indices in defining Table?
@kguler, +1. Should have thought of that one. I suspect anything that uses Range and functions that work on packed arrays without unpacking will be fast.
Nov
6
comment solve recursive factorial function
RSolveValue[{a[n + 1] - (n + 1)*a[n] == 17160, a[10] == 10}, a[n], n] should work. Note (n + 1) rather than [n + 1].
Nov
4
comment How to simplify only the lowest level of a nested expression
You say that A, B, ..., J represent "expressions not containing any brackets". I am very skeptical of this claim. Remember that even basic expressions such as a + b, a b, and {a, b} are just display forms for Plus[a ,b], Times[a, b], and List[a ,b]. I think you need to show us what A, B, ..., J really are.
Oct
28
comment Importing data from files designated in an InputString dialog box
I do not think this question should be closed. It does not exhibit a trivial mistake nor will a useful answer be easily found in the documentation. This question brings up some serious issues concerning how to work with InputString and Import and how to defend against bad input from a user.
Oct
27
comment Frontend: Adding cell-type choices to the “Choose how to enter input” drop-down
@rdjain1. If you are willing to accept the shortcuts as assigned, you won't need to define a new stylesheet, but if you want to change the assignments to move a shortcut from a style that has one, which you don't use, to style, which doesn't have one that you do use, you will have to derive a new new style sheet or modify the built-in one.
Oct
26
comment Second order differential equation with boundary conditions solving repeatedly
1) ClearAll; accomplishes nothing; maybe you want Clear["Global*"]. 2) Each of your definitions of pcw` overrides the previous one, so that only the last definition pcw[x_] := (W + x)/(2*W) remains in effect at the end. Did you intend that?
Oct
26
comment Poets of the 19th century
@belisarius. Don't think Joe Stalin qualifies. His poetic work was confined to the 20th century.
Oct
26
comment Poets of the 19th century
Love the title.
Oct
24
comment Iterations with Table?
This question appears to be off-topic because it is not formulated in English.
Oct
24
comment Make a series of points curl
An aside: instead of typing out a list of regularly spaced vectors along the x-axis, consider pts = Array[{#, 0, 0} &, 5];
Oct
20
comment How to use a C compiler without having SystemModeler
I have no knowledge of the Windows platform. I make no recommendation.
Oct
20
comment How to use a C compiler without having SystemModeler
Yes, you must have a C compiler install on your system to use it.
Oct
20
comment How to use a C compiler without having SystemModeler
You do not need SystemModeler to compile code in Mathematica.
Oct
20
comment How to fix the order in which text appears in an axis label (V7)
As nobody has mentioned the elephant in the room, I will. You have expressed your label text as a multiplication and Mathematica is doing its normal lexical reordering on it.
Oct
20
comment Equation of a transformed (roatted) ellipsoid
I am having trouble with trying to understand what you are asking. 1) you use left-handed coordinate system in your diagram. This in not consistent with Mathematica's way of plotting with a right-handed coordinate system. 2) You ask about doing a rotation about the y-axis, but your diagram shows a translation along the x-axis. 3) you introduce a parameter h in you volume expression without explanation or defintion.