45,965 reputation
394195
bio website halirutan.de
location Leipzig, Germany
age
visits member for 2 years, 7 months
seen 2 hours ago

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


2d
comment Trial version 10 vs Version 10 Prerelease 13
I can tell you that for me the Shadow messages was due a paclet in my .Mathematica user folder. I just deleted this one. For me it was under .Mathematica/Paclets/Configuration and I used fgrep to search for FailedQ to find the problematic file.
Aug
15
comment Why am I getting a kernel crash on Chop?
I cannot reproduce this on Ubuntu Linux 12.04, M 10.0.0
Aug
15
comment Is there any method can set the Package file as read-only or encrypt it?
Please see the Encode function.
Aug
15
comment Convert spectral distribution to RGB color
What makes you think that you can input an arbitrary continuous wavelength spectrum and create with a (highly monitor specific) mixture of 3 other wavelength spectra (namely red, green and blue) light which gives your brain the same impression as it would have seen the original spectrum?
Aug
14
comment Avoid creation of OwnValues when inserting transformation rules into Experimental`OptimizeExpression
You wrote I convert these into equations, this is not true. An equation in Mathematica is something like lhs==rhs but you use Set (=, only one =) which is the assignment operator. I'm pretty sure that you don't want this in the first place.
Aug
10
awarded  Nice Answer
Aug
8
answered Combining images with CUDA
Aug
7
comment Combining images with CUDA
@AlexeyBobrick About your clarification point (2): By doesn't look as good, do you mean the result? If you speak of Image Add like your caption suggests, then I am thinking about a real image processing image add where there is no such thing as antialiasing. You do direct pixel-by-pixel operations without adjusting something else. Can you give a specific example about what you mean? Btw, do you know the difference between an image add and setting an image region which is what Inset does?
Aug
7
comment Combining images with CUDA
.. CUDA device. For this, you have to allocate 1000^2 and 10^2 pixel in the device memory. Then you have to write access each of these pixel while you copy the image. This alone makes 1000100 of the write accesses (you have to read those locations from main memory too). Then you set those 10^2 region in your CUDA device and after this, you copy (again read access in the CUDA and allocation and write access in main memory) those 1000^2 back to main memory. Surely, using memcpy will be faster by magnitudes, but nevertheless work is tremendous compared to simply setting 100 memory locations.
Aug
7
comment Combining images with CUDA
@AlexeyBobrick I don't speak about Inset, I speak about setting array elements explicitly in a vectorized way like Simon suggested. Let me make my point clear, for this specific problem where we want to set a 10x10 region in a 1000x1000 image, we have the following to do when using high-level Mathematica: The 1000^2 image is already in main-memory, because, well, we already have it in Mathematica, and Mathematica can access his own memory. Therefore, setting a 10^2 region is similar to 100 write accesses. Compare this to the CUDA approach: First, you have to transfer both images to your..
Aug
6
comment Combining images with CUDA
I would be surprised when a CUDA function for this problem is faster than a normal Mathematica function. Copying both images to CUDA memory and copying the result back, only for setting pixel values? This sounds like a bad plan and too much overhead, especially since setting an array like Simon showed should be a vectorized operation anyway.
Aug
5
comment Counting and extracting hit circles/triangles for randomly chosen points
@DavidCaliri Is there something missing in my answer. If this is not the case, would you consider accepting it as answer? Btw, you haven't accepted an answer on your TeX question either.
Aug
4
comment Using ListPlot and Joined, how to keep markers in colour but make all joining lines gray?
@Öskå Then use (ColorData[1] /@ {1, 2, 3}) as option-value of MeshStyle.
Aug
4
answered Using ListPlot and Joined, how to keep markers in colour but make all joining lines gray?
Aug
1
comment How to group each element with each consecutive elements in one head
@alancalvitti Nope, I never used Fortran. Seems to be some other influence.
Aug
1
comment How to group each element with each consecutive elements in one head
@eldo Hehe, haliturutan sounds a bit like Truthahn in German :-) I edited the answer.
Aug
1
revised How to group each element with each consecutive elements in one head
added 201 characters in body
Aug
1
awarded  Nice Answer
Jul
31
comment Faster Alternative to DeleteDuplicates for deleting elements in list
Have you searched the forum? There are some threads about his, for instance here mathematica.stackexchange.com/a/35214/187
Jul
31
answered How to group each element with each consecutive elements in one head