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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
...e to go with @Moody_Mudskipper's answer: Using .drop=FALSE can give potentially unexpected results when one or more grouping variables are not coded as factors. See examples below:
library(dplyr)
data(iris)
# Add an additional level to Species
iris$Species = factor(iris$Species, levels=c(levels(ir...
How to alter SQL in “Edit Top 200 Rows” in SSMS 2008
...swered Jan 5 '10 at 8:29
David HallDavid Hall
30.2k1010 gold badges8484 silver badges119119 bronze badges
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Boolean operators && and ||
...es the longer form "appropriate for programming control-flow and [is] typically preferred in if clauses."
So you want to use the long forms only when you are certain the vectors are length one.
You should be absolutely certain your vectors are only length 1, such as in cases where they are funct...
Git: How to rebase to a specific commit?
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For me, this doesn't actually do what's intended. As far as I can tell, it tries to rebase onto the "last common ancestor" of topic and commitB.
– Dan Lenski
Jan 26 '15 at 18:20
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Remove duplicate values from JS array [duplicate]
...olution is O(n^2), making it inefficient.
– Casey Kuball
Sep 21 '17 at 16:35
4
I really wish in 2...
What is a “slug” in Django?
When I read Django code I often see in models what is called a "slug". I am not quite sure what this is, but I do know it has something to do with URLs. How and when is this slug-thing supposed to be used?
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What are the lesser known but useful data structures?
There are some data structures around that are really useful but are unknown to most programmers. Which ones are they?
83 A...
NPM clean modules
Is there a way to get npm to unbuild all the modules under node_modules? Something like npm rebuild that removes all build artifacts but doesn't rebuild them?
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Is it possible to “decompile” a Windows .exe? Or at least view the Assembly?
...ious to see what it does without infecting myself. I know that you can't really decompile an .exe, but can I at least view it in Assembly or attach a debugger?
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Do you have to put Task.Run in a method to make it async?
... numbers for the sake of this example, granted, it's no processing time at all, it's just a matter of formulating an example here.
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