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Repairing Postgresql after upgrading to OSX 10.7 Lion
I recently upgraded to OSX 10.7, at which point my rails installation completely borked when trying to connect to the psql server. When I do it from the command line using
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How do I make a list of data frames?
...to your question, but you want to use = and not <- within the function call. If you use <-, you'll end up creating variables y1 and y2 in whatever environment you're working in:
d1 <- data.frame(y1 <- c(1, 2, 3), y2 <- c(4, 5, 6))
y1
# [1] 1 2 3
y2
# [1] 4 5 6
This won't have the s...
What killed my process and why?
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I just wrote a program that malloc'd memory in an inifite loop. After the system got slow, "Killed" was displayed in the terminal and the process was terminated. The file /var/log/kern.log contained a lot of info about the termination. -Thanks for the...
getting the last item in a javascript object
...f you create an associative array in JS using the array markers [] it is really an object. JS does not have associative arrays as such, arrays have indexed access and sequence; objects have associative property access, non-sequential.
– Orbling
Nov 30 '10 at 19...
Efficient way to remove keys with empty strings from a dict
I have a dict and would like to remove all the keys for which there are empty value strings.
17 Answers
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Display a tooltip over a button using Windows Forms
...ying tool tips for multiple elements on a single form.
Say your button is called MyButton.
Add a ToolTip control (under Common
Controls in the Windows Forms
toolbox) to your form.
Give it a
name - say MyToolTip
Set the "Tooltip on MyToolTip" property of MyButton (under Misc in
the button property ...
Adding div element to body or document in JavaScript
...0%;opacity:0.3;z-index:100;background:#000;"></div>';
Edit:-
Ideally you should use body.appendChild method instead of changing the innerHTML
var elem = document.createElement('div');
elem.style.cssText = 'position:absolute;width:100%;height:100%;opacity:0.3;z-index:100;background:#000';...
Create a .txt file if doesn't exist, and if it does append a new line
... come i wont see that before? Damn... I felt like a total dumb thanks. I really preciate these kinda good answers.
– Berker Yüceer
Mar 28 '12 at 13:07
7
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Copy files without overwrite
I just can't seem to find a way on the command line to say "copy all the files from directory A to directory B, but if the file already exists in directory B, don't overwrite it, no matter which file is newer, and don't prompt me."
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What to return if Spring MVC controller method doesn't return value?
I am using jQuery's $.getJSON() to make asynchronous calls to my simple Spring MVC backend. Most of the Spring controller methods look like this:
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