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bio website halirutan.de
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visits member for 2 years, 7 months
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Although I'm quite familiar with Mathematica, I always try to keep an open mind and don't use it as golden hammer. I'm particularly good at things that are fun, for instance


Jul
15
answered Command to insert item into list
Jul
15
comment Why is the new PositionIndex horribly slow?
I like to see this in a Wolfram Blog post and I already hear the first paragraph: "In the new Wolfram Language we implemented this new kind of thing or as we called it complexity speed-up... the harder your problems get, the faster Mathematica will solve them!"
Jul
15
comment possible bug in Mathematica TeXForm? Generating \left\left
The problematic part seems to be that inside Abs is an expression which possibly requires scaled boundaries, because the expression is too large. Therefore, this works TeXForm[Abs[x + 1]] while this TeXForm[Abs[x + 1/2]] is introducing the extra left/right pair. Can find more notation like Abs and Norm that surround an expression?
Jul
14
comment Warning and Errors during Compile
@Karsten7. I have added this information to the answer, because my first version did not describe the issue properly.
Jul
14
revised Warning and Errors during Compile
added 479 characters in body
Jul
14
comment Autocomplete of non-global functions
I guess explicitly typing Notebook`My is not an option? :-)
Jul
14
comment Warning and Errors during Compile
@Karsten7. No, usually numbers like 1.0 are just converted to integer by casting: Compile[{{x, _Integer}}, x][300.0] On the other hand, when the conversion is not possible a message is thrown: Compile[{{x, _Integer}}, x][300.1] The message in the example is thrown because z is not localized by Module. After that the call cf[3, 300.] runs without message.
Jul
14
answered Warning and Errors during Compile
Jul
14
comment Optimizing a functional using variational calculus
your first error is that you use x0 = FindRoot[Veff[x] == U[-1, -1], {x, -0.2}], because this results in x0 being a rule like x->... but you only want the value.
Jul
14
revised Setting $RecursionLimit crashes Mathematica 10
added 249 characters in body
Jul
14
comment Why doesn't a Composition[] hold its arguments and what can be done about it?
As for your example: using the shorthand syntax, you need braces around (2+2) anyway. Isn't it easier to just write ToString@*HoldForm@Unevaluated[2 + 2] than bending the system? Or maybe ToString@*HoldForm@*Plus @@ {2, 2} in this specific case. I guess reimplementing Composition is not a good idea. Although it works here, in general Composition can be used with e.g. InverseFunction which breaks this approach.
Jul
14
comment Why doesn't a Composition[] hold its arguments and what can be done about it?
When I think about some use-cases, I guess evaluating the arguments is more natural, because in f @* g @* h @ x it is not very likely that f, g or h hold their arguments anyway. On the other hand, people will maybe use the evaluation, where x is a variable containing a larger expression which needs to be evaluated. As for your option #1: I'm only aware of the Locked attribute of Locked, where a thing was changed which was already for very long in the core system.
Jul
14
comment How to prevent notebook from moving/reshuffling code around while one is typing?
The problem is, that the indenter cannot be adjusted this way. Maybe turning it off completely is really an option for you, but then you have to do all the linebreaks and indents by yourself. Otherwise you will have you code aligned at the left margin.
Jul
14
comment Setting $RecursionLimit crashes Mathematica 10
@Mr.Wizard Not reproducible on Linux with V10. But here, I just have to wait to make the kernel crash :-)
Jul
14
revised How to prevent notebook from moving/reshuffling code around while one is typing?
added 286 characters in body
Jul
14
answered How to prevent notebook from moving/reshuffling code around while one is typing?
Jul
14
comment speed up for computing MatrixExp
IdentityMatrix is not compilable. Maybe you gain another microsecond by using something which doesn't call MainEvaluate :-)
Jul
14
answered Equivalent of ReplaceAll for Associations?
Jul
14
revised Kernel crash after idle in version 10.0
Although not confirmed by Woflram, this is clearly a bug.
Jul
14
comment Kernel crash after idle in version 10.0
Confirmed! After 15 min of doing nothing my kernel crashed. Reported it to Wolfram and linked to this question.