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Remove columns from dataframe where ALL values are NA
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dplyr now has a select_if verb that may be helpful here:
library(dplyr)
temp <- data.frame(x = 1:5, y = c(1,2,NA,4, 5), z = rep(NA, 5))
not_all_na <- function(x) any(!is.na(x))
not_any_na <- function(x) all(!is.na(x))
> temp
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Favourite performance tuning tricks [closed]
...n-optimal query plan
Break up the Join
Can you break up the join?
Pre-select foreign keys into a temporary table
Do half the join and put results in a temporary table
Are you using the right kind of temporary table?
#temp tables may perform much better than @table variables with large volum...
Loaded nib but the 'view' outlet was not set
...is is Josh Justice proposal, but in a graphical way (pictures are mine):
Select File owner
On right hand side panel select custom class.
Enter the custom class name
On right hand side panel select oultets
Drag view outlet to view component
Finally the View Controller is instantiated with ...
Easiest way to upgrade eclipse 3.7 to 4.2 (Juno)
... is basically an "Eclipse without plugins". Run it (on a fresh workspace), select File -> Import -> Installation -> From existing Installation and point the wizard to your existing 3.7 directory. Check "Install latest versions", hit finish.
That will install the latest versions of the plug...
Notepad++ - How can I replace blank lines [duplicate]
...
Press Ctrl+H (Replace)
Select Extended from SearchMode
Put \r\n\r\n in Find What
Put \r\n in ReplaceWith
Click on Replace All
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How to move the cursor word by word in the OS X Terminal
...e sequences for you:
Open Terminal preferences (cmd+,);
At Settings tab, select Keyboard and double-click ⌥ ← if it's there, or add it if it's not.
Set the modifier as desired, and type the shortcut key in the box: esc+B, generating the text \033b (you can't type this text manually).
Repeat fo...
Calculate a MD5 hash from a string
... (
Encoding.UTF8.GetBytes(observedText)
)
select ba.ToString("x2")
);
}
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CSS “and” and “or”
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&& works by stringing-together multiple selectors like-so:
<div class="class1 class2"></div>
div.class1.class2
{
/* foo */
}
Another example:
<input type="radio" class="class1" />
input[type="radio"].class1
{
/* foo */
}
|| works by se...
Bad class file magic or version
... an Android SDK you should specify at which SDK you refer... (In my case I selected Java 7 because I was using this version) But it depends in your case too. Search online for other errors with the same name, you'll find a lot of information
– Marco Acierno
Jan...
Remove Project from Android Studio
...This threw me off on a mac too... first, you can't click on the project to select it or it launches the project... you have to trick it by moving your mouse over to highlight and then to make sure it sticks use the keyboard arrow keys up/down to highlight the one you want. Then fn+delete to remove i...