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Assign multiple columns using := in data.table, by group
What is the best way to assign to multiple columns using data.table ? For example:
2 Answers
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How to download HTTP directory with all files and sub-directories as they appear on the online files
There is an online HTTP directory that I have access to. I have tried to download all sub-directories and files via wget . But, the problem is that when wget downloads sub-directories it downloads the index.html file which contains the list of files in that directory without downloading the fil...
Save modifications in place with awk
I am learning awk and I would like to know if there is an option to write changes to file, similar to sed where I would use -i option to save modifications to a file.
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sed edit file in place
...rying to find out if it is possible to edit a file in a single sed command without manually streaming the edited content into a new file and then renaming the new file to the original file name. I tried the -i option but my Solaris system said that -i is an illegal option. Is there a differe...
Are Java static initializers thread safe?
...ave. My question is therefore, can I guarantee that this static code block will only absolutely be called once when the class is first loaded? I understand I cannot guarantee when this code block will be called, I'm guessing its when the Classloader first loads it. I realize I could synchronize on t...
Best approach to remove time part of datetime in SQL Server
Which method provides the best performance when removing the time portion from a datetime field in SQL Server?
23 Answers
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Does Firefox support position: relative on table elements?
When I try to use position: relative / position: absolute on a <th> or <td> in Firefox it doesn't seem to work.
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public friend swap member function
In the beautiful answer to the copy-and-swap-idiom there is a piece of code I need a bit of help:
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What it the significance of the Javascript constructor property?
...ad around Javascript's take on OO...and, like many others, running into confusion about the constructor property. In particular, the significance of the constructor property, as I can't seem to make it have any effect. E.g.:
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What is the difference between a var and val definition in Scala?
What is the difference between a var and val definition in Scala and why does the language need both? Why would you choose a val over a var and vice versa?
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