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OpenCV C++/Obj-C: Detecting a sheet of paper / Square Detection
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This is a recurring subject in Stackoverflow and since I was unable to find a relevant implementation I decided to accept the challenge.
I made some modifications to the squares demo present in OpenCV and the resulting C++ code below is able to detect a sheet of paper ...
Why doesn't Ruby support i++ or i-- (increment/decrement operators)?
The pre/post increment/decrement operator ( ++ and -- ) are pretty standard programing language syntax (for procedural and object-oriented languages, at least).
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Quicksort: Choosing the pivot
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Choosing a random pivot minimizes the chance that you will encounter worst-case O(n2) performance (always choosing first or last would cause worst-case performance for nearly-sorted or nearly-reverse-sorted data). Choosing the middle el...
Is R's apply family more than syntactic sugar?
...regarding execution time and / or memory.
5 Answers
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Swapping column values in MySQL
I have a MySQL table with coordinates, the column names are X and Y. Now I want to swap the column values in this table, so that X becomes Y and Y becomes X. The most apparent solution would be renaming the columns, but I don't want to make structure changes since I don't necessarily have permission...
Normalize data in pandas
Suppose I have a pandas data frame df :
5 Answers
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How to pip install a package with min and max version range?
...tall a package with both a minimum version ( pip install package>=0.2 ) and a maximum version which should never be installed (theoretical api: pip install package<0.3 ).
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Why does this method print 4?
I was wondering what happens when you try to catch an StackOverflowError and came up with the following method:
7 Answers
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Wolfram's Rule 34 in XKCD [closed]
...1110. The digit of least significance is zero. This means that if the cell and its neighbors match rule 0 above, it turns white/negative/0/false/whatever. The second least significant digit is one, so if the cell and its neighbors match rule 1 above, it turns black/positive/1/true/whatever`, etc. et...
How do I split a string so I can access item x?
...ourceText)) SET @w_Length = DATALENGTH( RTRIM( LTRIM( @p_SourceText))) and not SET @p_SourceText = RTRIM( LTRIM( @p_SourceText)) SET @w_Length = DATALENGTH( @p_SourceText)?
– Beth
Sep 29 '10 at 15:13
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