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How to remove last n characters from every element in the R vector
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Here is an example of what I would do. I hope it's what you're looking for.
char_array = c("foo_bar","bar_foo","apple","beer")
a = data.frame("data"=char_array,"data2"=1:4)
a$data = substr(a$data,1,nchar(a$data)-3)
a should now contain:
data data2
1 foo_ 1
2 bar_ 2...
Are C# events synchronous?
...o the event.
I too was curious about the internal mechanism of event and its related operations. So I wrote a simple program and used ildasm to poke around its implementation.
The short answer is
there's no asynchronous operation involved in subscribing or invoking the events.
event is impleme...
Append values to query string
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You could use the HttpUtility.ParseQueryString method and an UriBuilder which provides a nice way to work with query string parameters without worrying about things like parsing, url encoding, ...:
string longurl = "http://somesite.com/news.php?artic...
Declare a block method parameter without using a typedef
Is it possible to specify a method block parameter in Objective-C without using a typedef? It must be, like function pointers, but I can't hit on the winning syntax without using an intermediate typedef:
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How can I convert a series of images to a PDF from the command line on linux? [closed]
...ed to use ls for anything apart from displaying files... i.e. do not parse it's output. find is a much more suitable tool. Here is an example convert $(find -maxdepth 1 -type f -name 'page*.png' | sort -n | paste -sd\ ) output.pdf. Keep in mind that the aforementioned command will not work if your p...
What is the definition of “interface” in object oriented programming
...terface is one of the more overloaded and confusing terms in development.
It is actually a concept of abstraction and encapsulation. For a given "box", it declares the "inputs" and "outputs" of that box. In the world of software, that usually means the operations that can be invoked on the box (alo...
How do you round a float to two decimal places in jruby
... take a parameter in Ruby 1.9, not in Ruby 1.8. JRuby defaults to 1.8, but it is capable of running in 1.9 mode.
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Javascript: best Singleton pattern [duplicate]
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edited Jan 3 '19 at 5:52
answered Jul 18 '11 at 13:49
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Django admin: how to sort by one of the custom list_display fields that has no database field
...rder__count'
This way you only annotate inside the admin interface. Not with every query that you do.
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Stop all active ajax requests in jQuery
I have a problem, when submitting a form all active ajax request fail, and that triggers error event.
16 Answers
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