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Group by multiple columns in dplyr, using string vector input
...t contains bunch of wrapper functions like s_group_by, s_mutate, s_filter, etc that use string arguments. You can mix them with the normal dplyr functions. For example
cols = c("cyl","gear")
mtcars %.%
s_group_by(cols) %.%
s_summarise("avdisp=mean(disp), max(disp)") %.%
arrange(avdisp)
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Copy values from one column to another in the same table
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BEWARE : Order of update columns is critical
GOOD: What I want saves existing Value of Status to PrevStatus
UPDATE Collections SET PrevStatus=Status, Status=44 WHERE ID=1487496;
BAD: Status & PrevStatus both end up as 44
UP...
Catch All Bugs with BugTrap! - 开源 & Github - 清泛网移动版 - 专注C/C++及内核技术
... from my own library: collection classes, IO streams, built-in XML parser, etc. BugTrap DLL depends on zlib. I have included it in the archive to simplify building.
CrashExplorer depends on STL, Boost and WTL. Both libraries must be pre-installed on your computer.
Thank you!
I appreciate support,...
Local and global temporary tables in SQL Server
...wever it turned out that the parent stored procedure had to create them in order for them to be available to the children stored procedure calls. This was a sad thing, because we have a bunch of stored procedures that have to set up the tables the same way and call down into common sprocs. Will glo...
How to call another controller Action From a controller in Mvc
...ation. E.g. when using an IoC container all depdencies should be injected, etc.
– Mo Valipour
Nov 25 '13 at 16:37
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Does using final for variables in Java improve garbage collection?
... You can also use local variables instead of fields when it is possible in order to enhance memory garbage collection and to reduce referential ties.
– sivi
Mar 10 '14 at 9:21
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Why can't Python's raw string literals end with a single backslash?
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In order for you to end a raw string with a slash I suggest you can use this trick:
>>> print r"c:\test"'\\'
test\
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How do I convert a String object into a Hash object?
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Yes, but in order to do that you either need a full Ruby parser, or you need to know where the string came from in the first place and know that it can only generate strings, symbols, and numbers. (See also Toms Mikoss's answer about tru...
How to check if a string in Python is in ASCII?
...ce of your string (whether you read it from a file, input from a keyboard, etc.) may have encoded a unicode string in ascii to produce your string, but that's where you need to go for an answer.
Perhaps the question you can ask is: "Is this string the result of encoding a unicode string in ascii?" ...
Stop an input field in a form from being submitted
...for my inserted fields to be usable so that the user can change checkboxes etc. and then submit them to my javascript.
– Acorn
Jun 9 '10 at 17:05
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