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Aggregate / summarize multiple variables per group (e.g. sum, mean)
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Using the data.table package, which is fast (useful for larger datasets)
https://github.com/Rdatatable/data.table/wiki
library(data.table)
df2 <- setDT(df1)[, lapply(.SD, sum), by=.(year, month), .SDcols=c("x1","x2")]
setDF(df2) # convert back to dataframe
Using the plyr package
require(pl...
mysql error 1364 Field doesn't have a default values
...e. Removing that setting and restarting MySQL should fix the problem.
See https://www.farbeyondcode.com/Solution-for-MariaDB-Field--xxx--doesn-t-have-a-default-value-5-2720.html
If editing that file doesn't fix the issue, see http://dev.mysql.com/doc/refman/5.6/en/option-files.html for other possi...
Oracle SELECT TOP 10 records
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Remove substring from the string
...info can be seen in the documentation about other versions as well:
http://www.ruby-doc.org/core/classes/String.html#method-i-slice-21
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Does “\d” in regex mean a digit?
...MAScript Matching Behavior" section in Regular Expression Options.
Info: https://docs.microsoft.com/en-us/dotnet/standard/base-types/character-classes-in-regular-expressions#decimal-digit-character-d
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How to decide between MonoTouch and Objective-C? [closed]
...ective, obviously, but I think this is pretty zealotry-free:
Is this for fun or business? If you wanted to get into consulting in this area, you could make your $399 back very quickly.
Do you want to learn the platform inside-out, or do you "just" want to write apps for it?
Do you like .Net enough...
What is the difference between and ?
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Unresolved external symbol on static class members
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If you are using C++ 17 you can just use the inline specifier (see https://stackoverflow.com/a/11711082/55721)
If using older versions of the C++ standard, you must add the definitions to match your declarations of X and Y
unsigned char test::X;
unsigned char test::Y;
somewhere. You might...
Ruby replace string with captured regex pattern
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Calculating frames per second in a game
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I think it's the simplest and preferred way. You just to keep track of
cn: counter of how many frames you've rendered
time_start: the time since you've started counting
time_now: the current time
Calculating the fps in this case is as simple as evaluating this formula:
FPS = cn / (time_now -...