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Find the day of a week
...a.frame(date=c("2012-02-01", "2012-02-01", "2012-02-02"))
df$day <- weekdays(as.Date(df$date))
df
## date day
## 1 2012-02-01 Wednesday
## 2 2012-02-01 Wednesday
## 3 2012-02-02 Thursday
Edit: Just to show another way...
The wday component of a POSIXlt object is the numeric wee...
g++ undefined reference to typeinfo
...ollowing error (and found the solution online, but it's not present in Stack Overflow):
17 Answers
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Bash command to sum a column of numbers [duplicate]
... that I can pipe into that will sum a column of numbers. I just want a quick one liner that will do something essentially like this:
...
Android: how to check if a View inside of ScrollView is visible?
I have a ScrollView which holds a series of Views . I would like to be able to determine if a view is currently visible (if any part of it is currently displayed by the ScrollView ). I would expect the below code to do this, surprisingly it does not:
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jQuery scroll to element
... you have a button with the id button, try this example:
$("#button").click(function() {
$([document.documentElement, document.body]).animate({
scrollTop: $("#elementtoScrollToID").offset().top
}, 2000);
});
I got the code from the article Smoothly scroll to an element without a j...
Python - abs vs fabs
I noticed that in python there are two similar looking methods for finding the absolute value of a number:
4 Answers
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How many double numbers are there between 0.0 and 1.0?
This is something that's been on my mind for years, but I never took the time to ask before.
6 Answers
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How to get a list of file names in different lines
I want to get a list of all the files in a directory, like with ls , so that each filename will be on a seperate line, without the extra details supplied by ls -l . I looked at ls --help and didn't find a solution. I tried doing
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UILabel Align Text to center
...r 30 '18 at 11:58
Linus Unnebäck
14k99 gold badges5959 silver badges7575 bronze badges
answered Jul 12 '12 at 8:20
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What does “%.*s” mean in printf?
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You can use an asterisk (*) to pass the width specifier/precision to printf(), rather than hard coding it into the format string, i.e.
void f(const char *str, int str_len)
{
printf("%.*s\n", str_len, str);
}
...