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In the shell, what does “ 2>&1 ” mean?
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2671
File descriptor 1 is the standard output (stdout).
File descriptor 2 is the standard error (s...
Replace all 0 values to NA
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252
Replacing all zeroes to NA:
df[df == 0] <- NA
Explanation
1. It is not NULL what you ...
What is the ultimate postal code and zip regex?
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20 Answers
20
Active
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Optional Parameters with C++ Macros
...f arguments to a macro.
enum
{
plain = 0,
bold = 1,
italic = 2
};
void PrintString(const char* message, int size, int style)
{
}
#define PRINT_STRING_1_ARGS(message) PrintString(message, 0, 0)
#define PRINT_STRING_2_ARGS(message, size) PrintString(message, size, 0...
Five equal columns in twitter bootstrap
...tand how the 5 column grid is being used here:
http://web.archive.org/web/20120416024539/http://domain7.com/mobile/tools/bootstrap/responsive
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Ruby - elegantly convert variable to an array if not an array already
...t of the time, but for some cases like a hash, it messes it up.
Array([1, 2, 3]) # => [1, 2, 3]
Array(1) # => [1]
Array(nil) # => []
Array({a: 1, b: 2}) # => [[:a, 1], [:b, 2]]
[*[1, 2, 3]] # => [1, 2, 3]
[*1] # => [1]
[*nil] # => ...
What does tilde-greater-than (~>) mean in Ruby gem dependencies? [duplicate]
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207
It means "equal to or greater than in the last digit", so e.g. ~> 2.3 means
"equal to 2.3 o...
How do you calculate the average of a set of circular data? [closed]
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Rounding float in Ruby
...er, I can only use .round which basically turns it into an int, meaning 2.34.round # => 2. Is there a simple effect way to do something like 2.3465 # => 2.35
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