大约有 953 项符合查询结果(耗时:0.0207秒) [XML]

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Generate a heatmap in MatPlotLib using a scatter data set

...n't mean to be an idiot, but how do you actually have this output to a PNG/PDF file instead of only displaying in an interactive IPython session? I'm trying to get this as some sort of normal axes instance, where I can add a title, axis labels, etc. and then do the normal savefig() like I would do f...
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Which is faster: Stack allocation or Heap allocation

...a access." Declare e volatile, but volatile is often compiled incorrectly (PDF). Take the address of e inside the loop (and maybe assign it to a variable that is declared extern and defined in another file). But even in this case, the compiler may notice that -- on the stack at least -- e will alwa...
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Group vs role (Any real difference?)

...rence between roles and groups. http://profsandhu.com/workshop/role-group.pdf A group is a collection of users with a given set of permissions assigned to the group (and transitively, to the users). A role is a collection of permissions, and a user effectively inherits those permissions when he ac...
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Finding all possible combinations of numbers to reach a given sum

...ins and mathematical model of it at http://jaqm.ro/issues/volume-5,issue-2/pdfs/patterson_harmel.pdf (or Google coin change problem). By the way, the Scala solution by Tsagadai, is interesting. This example produces either 1 or 0. As a side effect, it lists on the console all possible solutions. It...
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How can I view the source code for a function?

...repository or Winston Chang's github mirror. Uwe Ligges's R news article (PDF) (p. 43) is a good general reference of how to view the source code for .Internal and .Primitive functions. The basic steps are to first look for the function name in src/main/names.c and then search for the "C-entry" na...
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What's the difference between __PRETTY_FUNCTION__, __FUNCTION__, __func__?

...ction_name http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1208r5.pdf went into C++20, so we have yet another way to do it. The documentation says: constexpr const char* function_name() const noexcept; 6 Returns: If this object represents a position in the body of a function, returns an im...
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Is it better to use std::memcpy() or std::copy() in terms to performance?

...do exactly what you ask. See this presentation on compiler optimisations (pdf). Here's what GCC does for a simple std::copy of a POD type. #include <algorithm> struct foo { int x, y; }; void bar(foo* a, foo* b, size_t n) { std::copy(a, a + n, b); } Here's the disassembly (with o...
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Generating an MD5 checksum of a file

...used this solution but it uncorrectly gave the same hash for two different pdf files. The solution was to open the files by specifing binary mode, that is: [(fname, hashlib.md5(open(fname, 'rb').read()).hexdigest()) for fname in fnamelst] This is more related to the open function than md5 but I th...
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In which order should floats be added to get the most precise result?

...ere are still brick-and-mortar libraries around. Alternatively, buying the PDF online costs $5-$15 (depending on whether you're an ACM member). Lastly, DeepDyve seem to be offering to lend the paper for 24 hours for $2.99 (if you're new to DeepDyve, you might even be able to get it for free as part ...
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Simple explanation of MapReduce?

...tion of MapReduce, see: Google's MapReduce Programming Model -- Revisited (PDF). share | improve this answer | follow | ...