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How to combine multiple conditions to subset a data-frame using “OR”?
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filter(df, v1 < 0.5 | v2 == "g")
Using sqldf:
library(sqldf)
sqldf('SELECT *
FROM df
WHERE v1 < 0.5 OR v2 = "g"')
Output for the above options:
v1 v2
1 0.26550866 a
2 0.37212390 b
3 0.20168193 e
4 0.94467527 g
5 0.06178627 j
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How to check if a particular service is running on Ubuntu
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For Ubuntu (checked with 12.04)
You can get list of all services and select by color one of them with 'grep':
sudo service --status-all | grep postgres
Or you may use another way if you know correct name of service:
sudo service postgresql status
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Where does R store packages?
...rature. Once you find it, go to the /etc subdirectory.
C:\R\R-2.10.1\etc
Select the file in this folder named Rprofile.site. I open it with VIM. You will find this is a bare-bones file with less than 20 lines of code. I inserted the following inside the code:
# my custom library path
.libPaths("C...
Recent file history in Vim?
...a lot of keys.. first to get a list of files, then to press q, and then to select a number. I believe the MRU plugin mentioned below is much better: stackoverflow.com/a/3171323/4752883 you have to press <leader> f, then either browse to the file with hjkl or other keys/search for the file nam...
In Mongoose, how do I sort by date? (node.js)
... error sort() only takes 1 Argument :
Post.find({}, {
'_id': 0, // select keys to return here
}, {sort: '-date'}, function(err, posts) {
// use it here
});
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How to pinch out in iOS simulator when map view is only a portion of the screen?
...ircles hovered over a table view on the bottom left causing the rows to be selected.
– Christopher
Jul 25 '12 at 22:08
2
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Postgis installation: type “geometry” does not exist
...ing following code
CREATE EXTENSION postgis;
In detail,
open pgAdmin
select (click) your database
click "SQL" icon on the bar
run "CREATE EXTENSION postgis;" code
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How to get current language code with Swift?
...u want to get the type en-En, you can use Locale.preferredLanguages[0]
2)
Select Project(MyApp)->Project (not Target)-> press + button into Localizations, then add language which you want.
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Reopen last closed tab in Visual Studio
...This will open the recent files menu, which you can then use the arrows to select one and open it by hitting Enter.
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MongoDb query condition on comparing 2 fields
...have a collection T , with 2 fields: Grade1 and Grade2 , and I want to select those with condition Grade1 > Grade2 , how can I get a query like in MySQL?
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