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1h
comment Buying a new computer (specifically for Mathematica)
@YvesKlett years ago, I converted a GeForce2 Ultra to a Quadro2 Pro. Then it was just a driver distinction, but now, the hardware is different (but not necessarily "better"). Nowadays, these cards are becoming so power- and space-constrained, that it is not economical to make the all-singing, all-dancing card and sell it off with features disabled at a lower price. They stratify the cards within a single market this way, but normally the reason for it is big dies, low yields, and many resulting partially working GPUs. Full-speed DP CUDA requires hardware that is absent from the gaming cards.
1h
comment Buying a new computer (specifically for Mathematica)
@Voo CPUs are not tested that thoroughly, and a cosmic ray could come along at any time... overclocking does cause problems, usually when done carelessly, with insufficient cooling, or without sufficient testing. If you have a formal proof of the correctness of your program, operating system, etc., (yeah right!), then it is time to run it multiple times on independent and dissimilar hardware to test consistency of the results. This is a little bit flippant, but verifying correctness is a hard (and important) problem. Not overclocking (with due care) is a fairly minor consideration.
1h
answered ListConvolve Memory Hemorrhage
1h
revised ListConvolve Memory Hemorrhage
edited tags
2h
revised Memory leak when looping over FindInstance in version 10.0.0
edited tags
2h
comment How can I create a class of matrices programmatically?
re: the bounties. In my opinion whuber is highly deserving. I've always appreciated his patient, careful, and highly mathematically literate answers. When he answers, one can normally expect a tour de force. Another worthy candidate is m_goldberg. Most of his answers are not highly voted, because their goal seems to be to help the OP more than to try to answer an interesting question. Their sheer number, and his many reviews and meta contributions, reflect an amazing and selfless effort, without which the site would certainly have been poorer.
3h
reviewed Approve Find and return the key with lowest value in association list
7h
comment How to generate normally distributed random number
@Kausik Excel's rand() function gives you a uniformly distributed result. To do exactly what you do in Excel in Mathematica (and plot the histogram to see that it is correct): Histogram[Total[RandomReal[{0, 1}, {10000, 12}], {2}] - 6]. The way David shows it, Mathematica generates these random variates directly already with a normal distribution, so there is no need to truncate the distribution or sum the variates obtained. (But you can if you want.)
7h
comment Help with Fourier analysis and filtering of an image
You should not try to transform the magnitude spectrum back to an image, because by working on the magnitudes only you have lost all phase information and the original image cannot be recovered from this. Use Fourier to get the complex-valued result consisting of magnitude and phase information. Zero out any parts of it that you don't like. Then, return to real space using InverseFourier. But, I agree with Simon: if this picture is your source data, it is a fool's errand (it has been downsampled to a ridiculous extent). Use the original STM data instead.
12h
comment Why does Mathematica “sleep” when I don't work at computer?
And which version of Mathematica, and which operating system, are you using?
13h
comment Why does Mathematica “sleep” when I don't work at computer?
This is really an extraordinary claim, which is probably why your question was downvoted. People are probably not going to run your time-consuming code to try to observe a problem that they most likely don't believe exists, so could you please provide some concrete and convincing evidence for what you observe as part of the question? Specifically, why should we believe it is a problem with Mathematica, rather than with your computer?
1d
comment How to export attributes or annotations to an HDF5 file?
Just wondering, is this resolved in version 10?
1d
revised Exporting multiple arrays in a single HDF5 file in Mathematica 7
deleted 74 characters in body; edited tags
1d
answered Exporting multiple arrays in a single HDF5 file in Mathematica 7
1d
comment How to invert the default order of polynomial?
Is this what you're looking for?
1d
reviewed Close In WolframAlpha, how can I make a Scatter Plot without connecting points?
1d
reviewed Close How to clear Mathematica's storage after a large computation?
1d
comment I made my own equation, how do I know if it already exists?
It is also worth noting that keeping research results secret and naming equations after yourself is not the done thing in mathematics and will quickly get you identified as a crank. Peer review is absolutely essential, because without this nobody will take you seriously. Universities receive a surprising number of inquiries of this nature and are unlikely to consider yours any different than the others, unless you present an unusually strong argument for why the result is new and useful.
1d
comment I made my own equation, how do I know if it already exists?
The way to have some equation/theorem named after you is to publish a paper showing how useful and interesting it is, and to have that paper cited many times by others who hopefully might decide to call it after you when they refer to it. Bear in mind that there are infinitely many possible equations, so finding a unique one is nothing special in itself; rather you should seek to prove to others that you were the first to discover it and that it is important to the field of mathematics. With that in mind, adding more detail to your question would be helpful.
2d
comment Local SEnsitivity Analysis
However, this site is not about "any modelling process". It is about the computer algebra software Mathematica. And modular arithmetic definitely has nothing to do with sensitivity analysis. So, do you think this is the correct site? Are you using Mathematica or Wolfram SystemModeler? If not, we cannot help you here.