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Speed up the loop operation in R
I have a big performance problem in R. I wrote a function that iterates over a data.frame object. It simply adds a new column to a data.frame and accumulates something. (simple operation). The data.frame has roughly 850K rows. My PC is still working (about 10h now) and I have no idea about the...
Executing multi-line statements in the one-line command-line?
I'm using Python with -c to execute a one-liner loop, i.e.:
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How set background drawable programmatically in Android
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How to add items to a spinner in Android?
How to add items to a spinner?
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Practical usage of setjmp and longjmp in C
Can anyone explain me where exactly setjmp() and longjmp() functions can be used practically in embedded programming? I know that these are for error handling. But I'd like to know some use cases.
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Formula to determine brightness of RGB color
I'm looking for some kind of formula or algorithm to determine the brightness of a color given the RGB values. I know it can't be as simple as adding the RGB values together and having higher sums be brighter, but I'm kind of at a loss as to where to start.
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Insert picture/table in R Markdown [closed]
So I want to insert a table AND a picture into R Markdown. In regular word document I can just easily insert a table (5 rows by 2 columns), and for the picture just copy and paste.
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Equivalent of “throw” in R
How does one "throw" an error in R? I have a function that takes a data frame and some column names and does stuff with them. If the columns don't exist, I want the function to stop and to stop all functions depending on it.
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How to “properly” create a custom object in JavaScript?
I wonder about what the best way is to create an JavaScript object that has properties and methods.
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Fastest way to determine if an integer's square root is an integer
I'm looking for the fastest way to determine if a long value is a perfect square (i.e. its square root is another integer):
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