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Convert data.frame columns from factors to characters
... can create a logical vector of which columns are factors, and use that to selectively apply factor
f <- sapply(bobf, class) == "factor"
bobc[,f] <- lapply(bobc[,f], factor)
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ERROR 1452: Cannot add or update a child row: a foreign key constraint fails
... table. Following query would be helpful to fetch those non-matching rows:
SELECT child_table.*
FROM child_table
LEFT JOIN parent_table
ON parent_table.referenced_column = child_table.referencing_column
WHERE parent_table.referenced_column IS NULL
Now, you can generally do one (or more) of th...
Rails: How to change the title of a page?
...In rails 3 content_for is smart enough to work correctly with caching (see selected answer).
– opsb
Nov 15 '11 at 10:41
4
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Start a git commit message with a hashmark (#)
...y that behavior is wanted.
git 2.0.x/2.1 (Q3 2014) will add an automatic selection for core.commentChar:
See commit 84c9dc2
When core.commentChar is "auto", the comment char starts with '#' as in default but if it's already in the prepared message, find another char in a small subset. This should...
What are some methods to debug Javascript inside of a UIWebView?
...e sure "Show Develop Menu in Menubar" is on.
From the Menu-bar (of Safari) select Develop -> iPhone Simulator -> [your webview page].
That's it !
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Converting many 'if else' statements to a cleaner approach [duplicate]
...s not what you need here, this isn't modelling a finite state machine it's selecting a different conversion strategy based on the input type so the strategy pattern is more appropriate.
– Paolo
Jan 3 '13 at 13:55
...
How can I disable a button in a jQuery dialog from a function?
...line that will be of use (under the "buttons" section.
var buttons = $('.selector').dialog('option', 'buttons');
You'll need to get the buttons collection from the dialog, loop through that to find which one you need, and then set the disabled attribute as I showed above.
...
How do I truncate a .NET string?
...inqpad extension methods)
var val = string.Concat(Enumerable.Range(0, 50).Select(i => i % 10));
foreach(var limit in new[] { 10, 25, 44, 64 })
new Perf<string> {
{ "newstring" + limit, n => new string(val.Take(limit).ToArray()) },
{ "concat" + limit, n => string....
Real-world examples of recursion [closed]
...( because you want to stop this fast ).
After processing a given person, select the person from the front of the queue and apply immunization if needed. Get all their contacts previously unvisited, and then test to see if they're infected.
Repeat until the queue of infected people becomes 0, and...
How to retrieve a file from a server via SFTP?
...mote-username", "remote-host" );
{
// "interactive" version
// can selectively update specified known_hosts file
// need to implement UserInfo interface
// MyUserInfo is a swing implementation provided in
// examples/Sftp.java in the JSch dist
UserInfo ui = new MyUserInfo();
ses...