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Drop data frame columns by name
...hose still not acquainted with the drop argument of the indexing function, if you want to keep one column as a data frame, you do:
keeps <- "y"
DF[ , keeps, drop = FALSE]
drop=TRUE (or not mentioning it) will drop unnecessary dimensions, and hence return a vector with the values of column y.
...
Error handling in getJSON calls
...cally (by configuring your AJAX calls before actually calling them) or specifically (with method chain).
'generic' would be something like:
$.ajaxSetup({
"error":function() { alert("error"); }
});
And the 'specific' way:
$.getJSON("example.json", function() {
alert("success");
})
.succ...
How to make a countdown timer in Android?
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What if I wanted to base the CountDownTimer on a set alarm? How do I know how many milisUntilFinished?
– Kala J
Nov 7 '14 at 12:54
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What is the fastest way to send 100,000 HTTP requests in Python?
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How much faster can you go if you want to talk with the SAME server each time, by persisting the connection? Can this even be done across threads, or with one persistent connection per thread?
– mdurant
Jan 12 '15...
Is it possible to import a whole directory in sass using @import?
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If you are using Sass in a Rails project, the sass-rails gem, https://github.com/rails/sass-rails, features glob importing.
@import "foo/*" // import all the files in the foo folder
@import "bar/**/*" // import all the...
Is it possible to use the instanceof operator in a switch statement?
...s I { void do() { doC() } ... }
Then you can simply call do() on this.
If you are not free to change A, B, and C, you could apply the visitor pattern to achieve the same.
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Why use HttpClient for Synchronous Connection
...tivity, but what I am doing is purely synchronous, so I cannot see any significant benefit over using HttpWebRequest .
5 A...
jQuery: Wait/Delay 1 second without executing code
...orms the check every second using setTimeout:
var check = function(){
if(condition){
// run when condition is met
}
else {
setTimeout(check, 1000); // check again in a second
}
}
check();
s...
How to pull a random record using Django's ORM?
...r than the accepted answer, note that this approach makes two SQL queries. If the count changes in between, it might be possible to get an out of bounds error.
– Nelo Mitranim
Sep 12 '15 at 9:37
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“Use the new keyword if hiding was intended” warning
...irtual or abstract) called Events which is being overridden by your class. If you intend to override it put the "new" keyword after the public modifier. E.G.
public new EventsDataTable Events
{
..
}
If you don't wish to override it change your properties' name to something else.
...