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Merge / convert multiple PDF files into one PDF
...er to provide out.pdf, or else it will overwrite the last file in your command, sigh.
– mlissner
Oct 19 '13 at 22:20
10
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How does python numpy.where() work?
I am playing with numpy and digging through documentation and I have come across some magic. Namely I am talking about numpy.where() :
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Access parent DataContext from DataTemplate
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I had problems with the relative source in Silverlight. After searching and reading I did not find a suitable solution without using some additional Binding library. But, here is another approach for gaining access to the parent DataContext by directly referencing an element of which you know the...
Group by month and year in MySQL
...Performance... my test of GROUP BY YEAR(date), MONTH(date) DESC; (~450 ms) and GROUP BY DATE_FORMAT(date,'%Y-%m') (~850 ms) on a InnoDB table with > 300,000 entries showed the former (the marked answer to this question) took ~half the time as the latter.
– ow3n
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Is git's semi-secret empty tree object reliable, and why is there not a symbolic name for it?
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So I guess it is safer to define a variable with the result of that command as your empty sha1 tree (instead of relying of a "well known value").
Note: Git 2.25.1 (Feb. 2020) proposes in commit 9c8a294:
empty_tree=$(git mktree </dev/null)
# Windows:
git mktree <NUL
And adds:
As a hi...
What is the difference between “AS” and “IS” in an Oracle stored procedure?
I see Oracle procedures sometimes written with "AS", and sometimes with "IS" keyword.
6 Answers
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HTTP 404 Page Not Found in Web Api hosted in IIS 7.5
...t using the VS 2010 debugging dev server. But I now deployed it to IIS 7.5 and I am getting a HTTP 404 error when trying to access the application.
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What does Redis do when it runs out of memory?
...estion but I am having a hard time finding the answer. How does Redis 2.0 handle running out of maximum allocated memory? How does it decide which data to remove or which data to keep in memory?
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What's the safest way to iterate through the keys of a Perl hash?
...ng each may in some way have unintended side effects. So, is that true, and is one of the two following methods best, or is there a better way?
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Why is transposing a matrix of 512x512 much slower than transposing a matrix of 513x513?
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The explanation comes from Agner Fog in Optimizing software in C++ and it reduces to how data is accessed and stored in the cache.
For terms and detailed info, see the wiki entry on caching, I'm gonna narrow it down here.
A cache is organized in sets and lines. At a time, only one set is u...