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Sort rows in data.table in decreasing order on string key `order(-x,v)` gives error on data.table 1.
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Update
data.table v1.9.6+ now supports OP's original attempt and the following answer is no longer necessary.
You can use DT[order(-rank(x), y)].
x y v
1: c 1 7
2: c 3 8
3: c 6 9
4: b 1 1
5: b 3 2
6: b 6 3
7: a 1 4
8: a 3 5
9: a 6 6
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How to put a label on an issue in GitHub if you are not a contributor / owner?
... I feel like a prick every time I submit something I clearly know to be a feature request as an issue... It would be nice to have a better way than just writing "feature request" in the body to indicate that that's the case.
– El Yobo
Aug 20 '13 a...
Interface vs Base class
...this you will have:
public class Dog : Mammal
public class Cat : Mammal
Now let's suppose there are other mammals, which we will usually see in a zoo:
public class Giraffe : Mammal
public class Rhinoceros : Mammal
public class Hippopotamus : Mammal
This will still be valid because at the core ...
SQL/mysql - Select distinct/UNIQUE but return all columns?
... Krakow
France Paris
France Marseille
Italy Milano
Now the query
SELECT country FROM locations
GROUP BY country
will result in:
--country--
France
Poland
Italy
However, the following query
SELECT country, city FROM locations
GROUP BY country
...throws an error in...
Has anyone used Coffeescript for a production application? [closed]
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About the Con', now with Source-Maps that isn't really an issue anymore, just compile with -m and you're good.
– omeid
Jun 7 '13 at 8:12
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How to import local packages without gopath
...t" way to do it. You should be using vendor capabilities, vgo, or dep (for now) that are enabled by default in Go 1.6; see. You basically add your "external" or "dependent" packages within a vendor directory; upon compilation the compiler will use these packages first.
Found. I was able import lo...
Detect URLs in text with JavaScript
...erflow.com';
var html = urlify(text);
console.log(html)
// html now looks like:
// "Find me at <a href="http://www.example.com">http://www.example.com</a> and also at <a href="http://stackoverflow.com">http://stackoverflow.com</a>"
So in sum try:
$$('#pad dl dd'...
how to mix links ( tag ) and headings ( tag ) in web standard?
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HTML5 updates this subject: it is now OK to wrap block-level elements with A's, as stated under another question: https://stackoverflow.com/a/9782054/674965 and here: http://davidwalsh.name/html5-elements-links
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Git Bash doesn't see my PATH
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because I was installing Go and this path contained the executable go.exe
Now Git bash was able to recognize the command:
go
Perhaps just a system reboot would have been enough in my case, but I'm happy that this solution work in any case.
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Create list of single item repeated N times
...'string'] * len(columns)
Mutable items
I've used Python for a long time now, and I have never seen a use-case where I would do the above with a mutable instance. Instead, to get, say, a mutable empty list, set, or dict, you should do something like this:
list_of_lists = [[] for _ in columns]
T...