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Reorder levels of a factor without changing order of values
I have data frame with some numerical variables and some categorical factor variables. The order of levels for those factors is not the way I want them to be.
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Difference between Big-O and Little-O Notation
What is the difference between Big-O notation O(n) and Little-O notation o(n) ?
4 Answers
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What are the options for storing hierarchical data in a relational database? [closed]
...in this thread suggested. Use an Adjacency List to maintain the hierarchy and use Nested Sets to query the hierarchy.
The problem up until now has been that the coversion method from an Adjacecy List to Nested Sets has been frightfully slow because most people use the extreme RBAR method known as ...
Use of *args and **kwargs [duplicate]
So I have difficulty with the concept of *args and **kwargs .
11 Answers
11
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Does anyone still use [goto] in C# and if so why? [closed]
I was wondering whether anyone still uses the "goto" keyword syntax in C# and what possible reasons there are for doing so.
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Linux error while loading shared libraries: cannot open shared object file: No such file or director
... no libpthread_rt.so.1 in that listing. You probably need to re-configure and re-build it so that it depends on the library you have, or install whatever provides libpthread_rt.so.1.
Generally, the numbers after the .so are version numbers, and you'll often find that they are symlinks to each othe...
How to convert byte array to string and vice versa?
I have to convert a byte array to string in Android, but my byte array contains negative values.
22 Answers
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Convert RGB to RGBA over white
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Take the lowest color component, and convert that to an alpha value. Then scale the color components by subtracting the lowest, and dividing by the alpha value.
Example:
152 converts to an alpha value of (255 - 152) / 255 ~ 0.404
152 scales using (152 - 1...
What is a Y-combinator? [closed]
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@Andre MacFie: I didn't comment on the effort, I commented on the quality. In general, the policy on Stack Overflow is that answers should be self contained, with links to more information.
– Jørgen Fogh...
What is the difference between _tmain() and main() in C++?
...n does.
_tmain is a Microsoft extension.
main is, according to the C++ standard, the program's entry point.
It has one of these two signatures:
int main();
int main(int argc, char* argv[]);
Microsoft has added a wmain which replaces the second signature with this:
int wmain(int argc, wchar_t* ...