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| bio | website | |
|---|---|---|
| location | Naples, Italy | |
| age | 25 | |
| visits | member for | 11 months |
| seen | May 8 at 0:28 | |
| stats | profile views | 47 |
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Jan 21 |
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What's the most “functional” way to do Cholesky decomposition? I guess it's because my code fails to work whenever a zero has been previously computed on the leading diagonal of the lower triangular matrix. I should have added an exception, but I was probably too lazy to do it at the time. :D I'm just wondering if there are any precision issues involved or if you are actually "supposed to" have a zero in that element, though. |
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Sep 25 |
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Why is my animation so slow? @YvesKlett Not much, actually. |
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Sep 25 |
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Why is my animation so slow? The Simplify is actually one my futile attempts at making this thing run faster. I have noticed that the problem is probably in the ParametricPlot3D, as it is present even if I do not combine the two plots, only using the former. This might actually be meaningful. |
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Sep 25 |
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Why is my animation so slow? I use MMA 8.0.1.0 on an Intel i3 machine running Windows 7, with 4GB DDR3 and a NVIDIA GeForce 310M. I am not sure what kinds of Timings would be useful, since the problem is not that it takes time to start, but rather that the animation looks very much "stop motion"-like. However, I have noticed that it strongly depends on the number of "particles" whose trajectory I track: this slowing becomes negligible at a RandomSample of about 10. |
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Jul 24 |
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Manipulating an arbitrary-precision ContourPlot Yeah, you are right. I hadn't thought about that. Since it is an input value, it is only as good as I can input it, and as it stands I can still use higher precision numbers via the input field under the slider if needed. Thanks! So, basically, there is no way to tell the Manipulate function to feed higher-precision numbers to its arguments "internally". Is this right? |
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Jul 24 |
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Manipulating an arbitrary-precision ContourPlot Won't SetPrecision get me "virtual" precision? |
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Jul 13 |
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How can I assign a Fit result to a function? @stevenvh On my computer (Mathematica v 8.0.1 on Win7) the code I suggested works just fine, even though J.M.'s solution is superior beyond a shadow of a doubt. |
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Jul 13 |
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How can I assign a Fit result to a function? @J.M. Touché. Adding Evaluate should have fixed the issue, though one may wonder if there is any point in keeping the SetDelayed at this point. Not a very good answer, I reckon. |
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Jul 1 |
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Can RecurrenceTable make use of CompiledFunction? However, on my laptop this solution gives a Timing of ~14 s, while the uncompiled version runs for ~2.5 s, making it actually worse, performance-wise! :O |
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Jul 1 |
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Can RecurrenceTable make use of CompiledFunction? @OleksandrR. It works. Why don't you state that as an answer? It is precisely what I've been looking for! :O |
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Jun 29 |
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Avoiding MainEvaluate in a CompiledFunction to fetch “global” variables I know, thanks. I usually use longer names for variables, but just this time I gave in to laziness. |
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Jun 29 |
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Avoiding MainEvaluate in a CompiledFunction to fetch “global” variables Works as intended! Thanks! |
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Jun 21 |
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Are there guidelines for avoiding the unpacking of a packed array? @Yu-SungChang Where can I find further information about your statement? E.g., does FoldList internally call Dimensions or does it truly unpack packed arrays? - Does this warrant its own question? |
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Jun 20 |
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Tridiagonal symmetric matrix eigenvalue using bisection @ruebenko, I hadn't thought about that! Thanks! What's surprising, however, is that numeig unpacks! And it seems it's because FoldList unpacks! This does not look nice. |
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Jun 11 |
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What's the most “functional” way to do Cholesky decomposition? @Mr.Wizard Well, I've been using Mathematica for little more than a year, so I guess it depends on your definition of "beginning user". :D Anyway, I probably will not test it on matrices larger than 20 x 20, so I realize my concern might be moot. Thank you! |
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Jun 11 |
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What's the most “functional” way to do Cholesky decomposition? It indeed looks better, but wouldn't Append make it actually run slower than the procedural approach? |
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Jun 11 |
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What's the most “functional” way to do Cholesky decomposition? Thanks for welcoming me! Anyway, I am aware of the existence of the built-in function and I have used it to test results for both implementations, but for my Computational Physics course I have to implement a Cholesky decomposition by myself. I am free to do it in whatever programming language I want, so I picked Mathematica since it is the one I am most familiar with. I know that the procedural implementation would be more than enough for my course, but I'm trying to learn functional programming as well by myself in the meanwhile. :) |
