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MPICH vs OpenMPI

...xtensive optimizations that make it the preferred implementation in nearly all cases. Feature Support from the Latest MPI Standard An orthogonal axis to hardware/platform support is coverage of the MPI standard. Here MPICH is usually far and away superior. MPICH has been the first implementation...
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How to append rows to an R data frame

... Not knowing what you are trying to do, I'll share one more suggestion: Preallocate vectors of the type you want for each column, insert values into those vectors, and then, at the end, create your data.frame. Continuing with Julian's f3 (a preallocated data.frame) as the fastest option so far, def...
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What does “@private” mean in Objective-C?

... (id)init { if (self = [super init]) { other = [[MySecondClass alloc] init]; // Neither MyFirstClass nor MySecondClass provided any // accessor methods, so if we're going to access any ivars // we'll have to do it directly, like this: other->publicNum...
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Efficiency of purely functional programming

...ssible asymptotic slowdown that can happen when programming purely functionally as opposed to imperatively (i.e. allowing side-effects)? ...
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Favourite performance tuning tricks [closed]

...les (possibly archive the deleted records) Consider doing this automatically once a day or once a week. Rebuild Indexes Rebuild Tables (bcp data out/in) Dump / Reload the database (drastic, but might fix corruption) Build new, more appropriate index Run DBCC to see if there is possible corru...
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calculating the difference in months between two dates

...or is it more related to an actual span of time? The logic for determining all of these rules is non-trivial, so you'll have to determine your own and implement the appropriate algorithm. If all you want is simply a difference in the months--completely disregarding the date values--then you can use...
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Creating a system overlay window (always on top)

...ng to create an always-op-top button/clickable-image which stays on top of all the windows all the time. 16 Answers ...
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How do I move an existing Git submodule within a Git repository?

... Since git 1.8.5, git mv old/submod new/submod works as expected and does all the plumbing for you. You might want to use git 1.9.3 or newer, because it includes fixes for submodule moving. The process is similar to how you'd remove a submodule (see How do I remove a submodule?): Edit .gitmod...
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HTTPS and SSL3_GET_SERVER_CERTIFICATE:certificate verify failed, CA is OK

I am using XAMPP for development. Recently I upgraded my installation of xampp from an old version to 1.7.3. 12 Answers ...
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What's the best Django search app? [closed]

... Haystack has been badly, if at all, supported for quite some time. I recommend you avoid it at this point. Maybe they will fix it in the future but its in a bad place now. – Aaron Schif Jul 31 '13 at 15:21 ...