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Group by multiple columns in dplyr, using string vector input
...xkghc5cdsvxvyv0ja = sample(LETTERS[1:3], 100, replace=TRUE),
value = rnorm(100)
)
# get the columns we want to average within
columns = names(data)[-3]
library(dplyr)
df1 <- data %>%
group_by_at(vars(one_of(columns))) %>%
summarize(Value = mean(value))
#compare plyr for reference...
Getting visitors country from their IP
I want to get visitors country via their IP... Right now I'm using this ( http://api.hostip.info/country.php?ip= ...... )
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Repeat a task with a time delay?
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You should use Handler's postDelayed function for this purpose. It will run your code with specified delay on the main UI thread, so you will be able to update UI controls.
private int mInterval = 5000; // 5 seconds by default, can be changed later
private Handler mHand...
Convert to/from DateTime and Time in Ruby
... answered Nov 11 '08 at 1:43
Gordon WilsonGordon Wilson
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How do you add Boost libraries in CMakeLists.txt?
I need to add Boost libraries into my CMakeLists.txt. How do you do it or how do you add it?
7 Answers
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Practical uses for the “internal” keyword in C#
Could you please explain what the practical usage is for the internal keyword in C#?
22 Answers
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Issue with adding common code as git submodule: “already exists in the index”
...code was just copied into the two projects. I created a separate git repo for the common code and removed it from the projects with the plan to add it as a git submodule.
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Generating all permutations of a given string
...an elegant way to find all the permutations of a string. E.g. permutation for ba , would be ba and ab , but what about longer string such as abcdefgh ? Is there any Java implementation example?
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Why are two different concepts both called “heap”?
Why are the runtime heap used for dynamic memory allocation in C-style languages and the data structure both called "the heap"? Is there some relation?
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What's the cleanest way of applying map() to a dictionary in Swift?
...l keys in the dictionary. I was hoping something like the following would work, but filter cannot be applied to dictionary directly. What's the cleanest way of achieving this?
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