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Summarizing multiple columns with dplyr? [duplicate]
I'm struggling a bit with the dplyr-syntax. I have a data frame with different variables and one grouping variable. Now I want to calculate the mean for each column within each group, using dplyr in R.
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How do I send a POST request as a JSON?
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If your server is expecting the POST request to be json, then you would need to add a header, and also serialize the data for your request...
Python 2.x
import json
import urllib2
data = {
'ids': [12, 3, 4, 5, 6]
}
req = urllib2.Req...
NSLog with CGPoint data
...first answer is the easiest and lightest weight way. But this gets me both x and y from the CGPoint in one set. Nice :) Great tool :)
– Spanky
Sep 25 '09 at 18:29
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How to center align the cells of a UICollectionView?
... layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
return UIEdgeInsetsMake(0, 100, 0, 0);
}
You will have to play around with that number to figure out how to force the content into a single line. The first 0, is the top edge argument, you could a...
Can't use method return value in write context
...erence (in order to check whether that reference points to something that exists), and PHP before 5.5 didn't support references to temporary values returned from functions.
However, the real problem you have is that you use empty() at all, mistakenly believing that "empty" value is any different fr...
How to configure Mac OS X term so that git has color? [closed]
I've seen a Mac OS X git demo online in which it's configured to have multiple colors.
6 Answers
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Is the pImpl idiom really used in practice?
I am reading the book "Exceptional C++" by Herb Sutter, and in that book I have learned about the pImpl idiom. Basically, the idea is to create a structure for the private objects of a class and dynamically allocate them to decrease the compilation time (and also hide the private implementatio...
Set cookie and get cookie with JavaScript [duplicate]
...en I choose a file, it should be saved to a cookie for about a week. The next time you open your HTML file, it should be the previous file you've chosen.
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Mac OS X Terminal: Map option+delete to “backward delete word”
... to map it from Preferences -> Settings -> Keyboard, but the "key" combo box has only "forward delete" but no "delete". My keyboard on the other hand has only "delete" and no "forward delete"!
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Extract a dplyr tbl column as a vector
...umn a bit nicer (easier to type, and easier to read):
pull <- function(x,y) {x[,if(is.name(substitute(y))) deparse(substitute(y)) else y, drop = FALSE][[1]]}
This lets you do either of these:
iris2 %>% pull('Species')
iris2 %>% pull(Species)
iris2 %>% pull(5)
Resulting in...
[1] ...