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Finding quaternion representing the rotation from one vector to another
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Be aware that this does not handle the case of parallel vectors (both in the same direction or pointing in opposite directions). crossproduct will not be valid in these cases, so you first need to check dot(v1, v2) > 0.999999 and dot(v1, v2) < -0.999999, respectively, ...
Is AsyncTask really conceptually flawed or am I just missing something?
...p with different solutions to it, which I am not happy with since they are all massive hacks. I still cannot believe that a class that flawed in design made it into the framework and no-one is talking about it, so I guess I just must be missing something.
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PHP_SELF vs PATH_INFO vs SCRIPT_NAME vs REQUEST_URI
I am building a PHP application in CodeIgniter. CodeIgniter sends all requests to the main controller: index.php . However, I don't like to see index.php in the URI. For example, http://www.example.com/faq/whatever will route to http://www.example.com/index.php/faq/whatever . I need a reliable...
In-memory size of a Python structure
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Yep. The "4 higher" actually mostly look like "rounding up to a multiple of 8" which I believe is correct for the way malloc behaves here. No idea why decimal gets so distorted (with pympler on 2.6, too).
– Alex Martelli
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Why use AJAX when WebSockets is available?
...s opens up new application domains to browser applications that were not really possible using HTTP and AJAX (interactive games, dynamic media streams, bridging to existing network protocols, etc).
However, there is certainly an overlap in purpose between WebSockets and AJAX/Comet. For example, whe...
Is Java really slow?
...my opinion, this is the main reason Java still has a bad reputation, especially server-side. This makes the String problems exponentially worse. Some simple mistakes are common: objects are often used in place of primitives, reducing performance and increasing memory use. Many Java libraries (includ...
Disable assertions in Python
...trate each.
For the whole process
Using the -O flag (capital O) disables all assert statements in a process.
For example:
$ python -Oc "assert False"
$ python -c "assert False"
Traceback (most recent call last):
File "<string>", line 1, in <module>
AssertionError
Note that by di...
Download attachments using Java Mail
Now that I`ve downloaded all the messages, and store them to
4 Answers
4
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How to design a database for User Defined Fields?
...rformance is the primary concern, I would go with #6... a table per UDF (really, this is a variant of #2). This answer is specifically tailored to this situation and the description of the data distribution and access patterns described.
Pros:
Because you indicate that some UDFs
have values for a...
Circle line-segment collision detection algorithm?
... exdx + eydy - dxh - dyk ) +
ex2 + ey2 -
2exh - 2eyk + h2 + k2 - r2 = 0
Finally,
t2( _d * _d ) + 2t( _e * _d - _d * _c ) + _e * _e - 2( _e*_c ) + _c * _c - r2 = 0
*Where _d is the vector d and * is the dot product.*
And then,
t2( _d * _d ) + 2t( _d * ( _e - _c ) ) + ( _e - _c ) * ( _e - _c ) - r2 = ...