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seen Oct 28 at 14:59

Feel free to correct the grammar mistakes in my posts.


Oct
14
comment Has this implementation of FDM touched the speed limit of Mathematica?
@RunnyKine More likely to be a defect of TDM-GCC, I think. Today I learned the basic syntax of C++ for several hours and rewrited the piece of code with it in order to find out if 12s touches the limit of my hardware. The result is, with optimization flag -O3 or -Ofast, the C++ version only costs about 8s in my computer: that's a 1.5X speedup just as you got. So the compiler failed to dig out all the potential of the code.
Oct
13
revised Has this implementation of FDM touched the speed limit of Mathematica?
added 2 characters in body
Oct
11
comment Has this implementation of FDM touched the speed limit of Mathematica?
@AlexeyBobrick No, it won't. ParallelDo isn't in the list, the result of CompilePrint also shows it's indeed not compiled.
Oct
11
revised Has this implementation of FDM touched the speed limit of Mathematica?
added 2 characters in body
Oct
11
comment Has this implementation of FDM touched the speed limit of Mathematica?
@RunnyKine With TDM-GCC 4.8.1, Vista 32bit, ez[[j]] = Compile`GetElement[ez, j]…… even makes the code a bit slower. The Compile`GetElement trick is really amazing, now the code only takes about 13s for steps = 10^7 in my computer, as fast as the Julia version (with the @inbounds macro added). And if I set "CompileOptions"->"-Ofast" when loading the compiler, the timing will reduce to about 12.3s!
Oct
10
comment C compiler options passed by Mathematica
Can it be an issue of compiler installation? Maybe quotation isn't used in some places when the compiler is installed, and it doesn't cause any problem when called from command line but does when called from Mathematica?
Oct
10
reviewed Approve suggested edit on Repeatedly randomly redrawing part of a random sample that matches a certain criterion
Oct
10
reviewed Approve suggested edit on How can I randomize order of elements in a list?
Oct
10
reviewed Approve suggested edit on How can I generate and randomly assign color to annular sectors?
Oct
10
awarded  Nice Question
Oct
10
awarded  Nice Question
Oct
10
reviewed Reject suggested edit on Deleting all characters in a string that do not belong to a small set of elements
Oct
10
reviewed Reject suggested edit on Deleting all characters in a string that do not belong to a small set of elements
Oct
10
comment Bad performance of LengthWhile?
Response from Wolfram company: ……Thank you for your message and the link of the post. I have filed a report on this performance issue of LengthWhile and thank you for bringing it to our attention.……
Oct
10
revised I failed to solve a set of one-dimension fluid mechanics PDEs with NDSolve
Just some tiny modification. When I asked this, I didn't know "@ " can only be used to in the comment and the person you want to call should be also occurred under that post. BTW DNA refers to http://mathematica.stackexchange.com/users/204/drn
Oct
10
comment C compiler options passed by Mathematica
"C:\Program is not recognized……" seems that the white space in the path isn't recognized correctly. I'm not sure about the reason. Did you forget to add double quotation marks somewhere?
Oct
10
awarded  Promoter
Oct
10
comment Has this implementation of FDM touched the speed limit of Mathematica?
@AlexeyBobrick I'm sorry but this won't work, as the document said, Parallelization -> True only works together with RuntimeAttributes -> {Listable}, it just makes a Listable compiled function paralleled, while it's not the case of this question.
Oct
9
awarded  Nice Answer
Oct
9
comment Has this implementation of FDM touched the speed limit of Mathematica?
@AlexeyBobrick Just scaned this document and tried several flags in "CompileOptions" (-O3, -Ofast, etc.) but didn't get a speed-up… Could you give an example? (BTW -Ofast does help in speeding up this code :D)