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How do I delete rows in a data frame?
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The key idea is you form a set of the rows you want to remove, and keep the complement of that set.
In R, the complement of a set is given by the '-' operator.
So, assuming the data.frame is called myData:
myData[-c(2, 4, 6), ] # notice the -
Of course, don't forget to "reassign" ...
What is the difference between URI, URL and URN? [duplicate]
What's the difference between an URI, URL and URN? I have read a lot of sites (even Wikipedia) but I don't understand it.
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How to enumerate an enum with String type?
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print($0.rawValue)
}
Compatibility with earlier Swift versions (3.x and 4.x)
If you need to support Swift 3.x or 4.0, you may mimic the Swift 4.2 implementation by adding the following code:
#if !swift(>=4.2)
public protocol CaseIterable {
associatedtype AllCases: Collection where AllC...
Finding current executable's path without /proc/self/exe
...ecutable or a name that was found using $PATH.
Some shells, including bash and ksh, set the environment variable "_" to the full path of the executable before it is executed. In that case you can use getenv("_") to get it. However this is unreliable because not all shells do this, and it could be ...
What does ||= (or-equals) mean in Ruby?
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This question has been discussed so often on the Ruby mailing-lists and Ruby blogs that there are now even threads on the Ruby mailing-list whose only purpose is to collect links to all the other threads on the Ruby mailing-list that discuss this issue.
Here's one: The definitive list of ||= ...
Best way to do Version Control for MS Excel
... systems have you used with MS Excel (2003/2007)? What would you recommend and Why? What limitations have you found with your top rated version control system?
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How to recursively find and list the latest modified files in a directory with subdirectories and ti
I have several directories with several subdirectories and files in them. I need to make a list of all these directories that is constructed in a way such that every first-level directory is listed next to the date and time of the latest created/modified file within it.
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What are the aspect ratios for all Android phone and tablet devices?
I'm looking for a list of all screen aspect ratios for popular Android based Phones and Tablets.
5 Answers
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Use rvmrc or ruby-version file to set a project gemset with RVM?
I use RVM, the Ruby Version Manager to specify a Ruby version and a set of gems for each of my Rails projects.
5 Answers
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How can I use a file in a command and redirect output to the same file without truncating it?
...ly I want to take as input text from a file, remove a line from that file, and send the output back to the same file. Something along these lines if that makes it any clearer.
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