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Sample random rows in dataframe
...356774 -0.1640883
9 -0.3983045 0.7157506
10 -0.9060305 2.3234110
Then select some rows at random:
> df[sample(nrow(df), 3), ]
X1 X2
9 -0.3983045 0.7157506
2 -1.1334614 -0.1973846
10 -0.9060305 2.3234110
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MySQL load NULL values from CSV data
...can see empty strings '' when they download a csv (using IFNULL(Col,'') in SELECT INTO OUTFILE query) for excel but then uploads accept them as null vs having to deal with \N in the csv. Thanks!
– chrisan
Sep 29 '13 at 15:47
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Installing vim with ruby support (+ruby)
...by, and TCL but no GUI."
sudo apt-get install vim-rails
will install a "selection of vimscripts that make editing Ruby on Rails applications extremely easy." but as it depends on vim-full and vim-addon-manager, it will also install the vim-gnome version of the GUI, that is "a version of vim compi...
Selectors in Objective-C?
First, I'm not sure I really understand what a selector is. From my understanding, it's the name of a method, and you can assign it to a class of type 'SEL' and then run methods such as respondToSelector to see if the receiver implements that method. Can someone offer up a better explanation?
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ValidateRequest=“false” doesn't work in Asp.Net 4
...r. Maintains security and is extremely flexible since you can use it on a selective basis.
– cmartin
Jun 5 '15 at 18:38
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How to show android checkbox at right side?
... the layout , it should show (for a very short time) that the whole row is selected . how do you do that and simulate that it's a native effect?
– android developer
Apr 24 '12 at 10:52
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WordPress is giving me 404 page not found for all pages except the homepage
...n interface do the following:
Go to admin setting
Click on permalink and select post name in radio button.
Scroll down and you will see .htaccess code here like.
<IfModule mod_rewrite.c>
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FIL...
UIButton custom font vertical alignment
... doesn't actually appear in the IB screen mockup, although it does in font select drop down in IB.
– Pete
Sep 24 '11 at 16:31
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Which version of Perl should I use on Windows? [closed]
...able via ActiveState's repository.
Like most things, you should make your selection based on which distribution best meets your needs.
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Database: To delete or not to delete records
...re actively allowing an undelete. We also have the option to display it to select users as well, without much extra work.
If you're not actively seeking to fully restore the data, but you'd still like to keep it around for monitoring (or similar) purposes. I would suggest that you figure out (to th...