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data.table vs dplyr: can one do something well the other can't or does poorly?
...j and by together is by design. By keeping related operations together, it allows to easily optimise operations for speed and more importantly memory usage, and also provide some powerful features, all while maintaining the consistency in syntax.
1. Speed
Quite a few benchmarks (though mostly on g...
write a shell script to ssh to a remote machine and execute commands
...ame hostname "pwd; ls"
This will disable the host key check and automatically add the host key to the list of known hosts. If you do not want to have the host added to the known hosts file, add the option -o UserKnownHostsFile=/dev/null.
Note that this disables certain security checks, for exampl...
Detect whether there is an Internet connection available on Android [duplicate]
...er downtime, low signal, captive portals, content filters and the like can all prevent your app from reaching a server. For instance you can't tell for sure if your app can reach Twitter until you receive a valid response from the Twitter service.
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Access Denied for User 'root'@'localhost' (using password: YES) - No Privileges?
...ost, User, Password) VALUES ('%', 'root', password('YOURPASSWORD'));
GRANT ALL ON *.* TO 'root'@'%' WITH GRANT OPTION;
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JSON Stringify changes time of date because of UTC
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thanks... I actually found a great library here, blog.stevenlevithan.com/archives/date-time-format all you need to do this (maybe it will help you) , you pass false and it doesn't convert. var something = dateFormat(myStartDate, "isoDateTi...
Random strings in Python
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In many cases, random isn't really required. Rather, all you really need is unique.
– Chase Seibert
Jan 8 '10 at 19:48
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Proper way to exit iPhone application?
... it to exit due to certain user actions. After cleaning up memory the app allocated, what's the appropriate method to call to terminate the application?
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Why does MYSQL higher LIMIT offset slow the query down?
...e improvement. If there is no index usable by ORDER BY or the index covers all fields you need, you don't need this workaround.
– Quassnoi
Nov 24 '11 at 18:13
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Using Rails 3.1, where do you put your “page specific” JavaScript code?
To my understanding, all of your JavaScript gets merged into 1 file. Rails does this by default when it adds //= require_tree . to the bottom of your application.js manifest file.
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Int or Number DataType for DataAnnotation validation attribute
On my MVC3 project, I store score prediction for football/soccer/hockey/... sport game. So one of properties of my prediction class looks like this:
...