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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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How to check if a symlink exists
...urns true if the "file" exists and is a symbolic link (the linked file may or may not exist). You want -f (returns true if file exists and is a regular file) or maybe just -e (returns true if file exists regardless of type).
According to the GNU manpage, -h is identical to -L, but according to the ...
How do you compare structs for equality in C?
How do you compare two instances of structs for equality in standard C?
11 Answers
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Returning multiple values from a C++ function
Is there a preferred way to return multiple values from a C++ function? For example, imagine a function that divides two integers and returns both the quotient and the remainder. One way I commonly see is to use reference parameters:
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What is the best (idiomatic) way to check the type of a Python variable? [duplicate]
I need to know if a variable in Python is a string or a dict. Is there anything wrong with the following code?
10 Answers
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How to set Oracle's Java as the default Java in Ubuntu?
How do I change the value of JAVA_HOME in Ubuntu to point to Oracle's Java?
8 Answers
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What does (x ^ 0x1) != 0 mean?
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The XOR operation (x ^ 0x1) inverts bit 0. So the expression effectively means: if bit 0 of x is 0, or any other bit of x is 1, then the expression is true.
Conversely the expression is false if x == 1.
So the test is the same a...
Should you always favor xrange() over range()?
Why or why not?
12 Answers
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Variable declaration placement in C
...the same as in C++, but what are the variable declaration placement rules for C89/ANSI C?
8 Answers
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Does Python's time.time() return the local or UTC timestamp?
Does time.time() in the Python time module return the system's time or the time in UTC?
8 Answers
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