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Quickly reading very large tables as dataframes
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# sqldf as on SO
f <- file("test.csv")
system.time(SQLf <- sqldf("select * from f", dbname = tempfile(), file.format = list(header = T, row.names = F)))
## user system elapsed
## 10.21 0.47 10.73
ff / ffdf
require(ff)
system.time(FFDF <- read.csv.ffdf(file="test.csv",nro...
Visual Studio: How to show Overloads in IntelliSense?
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Ctrl+Shift+Space shows the Edit.ParameterInfo for the selected method, and by selected method I mean the caret must be within the method parentheses.
Here is the Visual Studio 2010 Keybinding Poster.
And for those still using 2008.
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Command to collapse all sections of code?
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You can also right click in the editor an select: Outlining -> Toggle All Outlining
– LBushkin
Jun 11 '09 at 18:11
25
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Is using Random and OrderBy a good shuffle algorithm?
...e naive version). Durstenfeld/Knuth achieve O(n) not by assignment, but by selection from a decreasing set and swapping. This way the random number selected may repeat and the algorithm only takes O(n).
– tvanfosson
Aug 17 '09 at 12:18
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Visual Studio 2013 and BitBucket
...oject!
In your "Solution Explorer", right click on your solution name, and select "Add Solution to Source Control ...".
Go to your "Team Explorer" and click on the "Manage Connections" icon on the top.
Double click on your Repository name under the "Local Git Repositories" section.
Now click on the ...
Why is Lisp used for AI? [closed]
...utes of macro work this week, I implemented an ad-hoc buggy version of SQL Select. It goes like this: (query SELECT * FROM dataset WHERE expr).
– Paul Nathan
Nov 12 '11 at 20:08
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Does List guarantee insertion order?
...I have for moving an item down one place in a list:
if (this.folderImages.SelectedIndex > -1 && this.folderImages.SelectedIndex < this.folderImages.Items.Count - 1)
{
string imageName = this.folderImages.SelectedItem as string;
int index = this.folderImages.SelectedIndex;
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Why does this async action hang?
...DBConnection.ExecuteAsync<ResultClass>(
ds => ds.Execute("select slow running data into result"));
}
What's the difference? There's now no awaiting anywhere, so nothing being implicitly scheduled to the UI thread. For simple methods like these that have a single return, there's no...
How to add an auto-incrementing primary key to an existing table, in PostgreSQL?
...t have to have a placeholder for it in the Insert statement. Then a simple select * into the target table auto populated this column. Here are the two SQL statements that I used on PostgreSQL 9.6.4.
ALTER TABLE target ADD COLUMN some_column SERIAL;
INSERT INTO target SELECT * from source;
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Where can I find my Azure account name and account key?
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Adding a new answer as Azure UI is updated.
So, after selecting the storage account(in my case its inAFlash) select Access keys option you will get the following screen shown in the screenshot
Here you see two key's Primary and secondary.
So, previously these were key1 and k...