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Convert data.frame columns from factors to characters
I have a data frame. Let's call him bob :
18 Answers
18
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How can one change the timestamp of an old commit in Git?
...c hash of the commit you're looking to fix.
This will invalidate that and all future hashes.
Example:
If you wanted to change the dates of commit 119f9ecf58069b265ab22f1f97d2b648faf932e0, you could do so with something like this:
git filter-branch --env-filter \
'if [ $GIT_COMMIT = 119f9ecf5...
Rails create or update magic?
I have a class called CachedObject that stores generic serialised objects indexed by key. I want this class to implement a create_or_update method. If an object is found it will update it, otherwise it will create a new one.
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How do I check if a Sql server string is null or empty
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@irfandar - Well, if you want to treat a string with all spaces as empty, go ahead use trim. Otherwise a string with all spaces is not empty.
– Martin Ba
Sep 2 '13 at 12:13
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WPF Blurry fonts issue- Solutions
...ems to make the font heavier
Playing around with these settings didn't really improve the underlying problem, but can help by reducing the color bleeding effect for sensitive users.
Another approach
The best advice the Text Clarity article gave was increasing the font size and changing the font....
Query to list number of records in each table in a database
... i.object_id = p.OBJECT_ID AND i.index_id = p.index_id
INNER JOIN
sys.allocation_units a ON p.partition_id = a.container_id
WHERE
t.NAME NOT LIKE 'dt%' AND
i.OBJECT_ID > 255 AND
i.index_id <= 1
GROUP BY
t.NAME, i.object_id, i.index_id, i.name, p.[Rows]
ORDER BY
o...
Cannot set content-type to 'application/json' in jQuery.ajax
...S header is used to find out if the request from the originating domain is allowed. Using fiddler, I added the following to the response headers from my server.
Access-Control-Allow-Origin: *
Access-Control-Allow-Headers: Content-Type
Access-Control-Allow-Methods: POST, GET, OPTIONS
Once the b...
Does “display:none” prevent an image from loading?
...tab of your browser's developer tools.
Note that if the browser is on a small CPU computer, not having to render the image (and layout the page) will make the whole rendering operation faster but I doubt this is something that really makes sense today.
If you want to prevent the image from loading...
Update Item to Revision vs Revert to Revision
...n that your workingcopy is out of date.
revert to this revision will undo all changes in your working copy which were made after the selected revision (in your example rev. 96,97,98,99,100)
Your working copy is now in modified state.
The file content of both scenarions is same, however in first c...
Is it possible to set a number to NaN or infinity?
...question over a second time!! Sorry! That said, it wouldn't hurt to say so all the same because it's an easy trap to fall into, NaN != NaN
– David Heffernan
Mar 25 '11 at 22:30
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