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Conditional Variable vs Semaphore
... that a piece of code is atomic, put a lock around it. You could theoretically use a binary semaphore to do this, but that's a special case.
Semaphores and condition variables build on top of the mutual exclusion provide by locks and are used for providing synchronized access to shared resources. ...
How to create a new object instance from a Type
...
Glad to have finally found this, but second call is not exactly right, missing a quote and parms reversed, should be: ObjectType instance = (ObjectType)Activator.CreateInstance("MyAssembly","MyNamespace.ObjectType");
– ...
How to change collation of database, table, column?
...
You need to either convert each table individually:
ALTER TABLE mytable CONVERT TO CHARACTER SET utf8mb4
(this will convert the columns just as well), or export the database with latin1 and import it back with utf8mb4.
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Confusion between numpy, scipy, matplotlib and pylab
...ncy of matplotlib.
If you run ipython --pylab an automatic import will put all symbols from matplotlib.pylab into global scope. Like you wrote numpy gets imported under the np alias. Symbols from matplotlib are available under the mpl alias.
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Calculate distance between 2 GPS coordinates
...y solution:
#include <math.h>
#include "haversine.h"
#define d2r (M_PI / 180.0)
//calculate haversine distance for linear distance
double haversine_km(double lat1, double long1, double lat2, double long2)
{
double dlong = (long2 - long1) * d2r;
double dlat = (lat2 - lat1) * d2r;
...
Should I Stop Stopwatch at the end of the method?
...o a Stopwatch isn't doing any work or eating cpu clock cycles between the calls to Start() and Stop(). Start() just sets a timestamp to now and Stop() calculates and saves the time elapsed since that. See source in coreclr: github.com/dotnet/corefx/blob/master/src/…
– Sammi
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How to install MySQLdb (Python data access library to MySQL) on Mac OS X?
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Update for those using Python3:
You can simply use conda install mysqlclient to install the libraries required to use MySQLdb as it currently exists. The following SO question was a helpful clue: Python 3 ImportError: No module named 'ConfigParser' . Installing mysqlclient will install...
How to post data in PHP using file_get_contents?
...Sending an HTTP POST request using file_get_contents is not that hard, actually : as you guessed, you have to use the $context parameter.
There's an example given in the PHP manual, at this page : HTTP context options (quoting) :
$postdata = http_build_query(
array(
'var1' => 'some...
How to determine height of UICollectionView with FlowLayout
...y question: I was completely searching in the wrong place, digging through all the documentation I could find on UICollectionView.
The simple and easy solution lies in the underlying layout: Just call collectionViewContentSize on your myCollectionView.collectionViewLayout property and you get the h...
Why does comparing strings using either '==' or 'is' sometimes produce a different result?
...l reasons: it is
inherently O(n) in the length of the
strings; it typically requires reads
from several regions of memory, which
take time; and the reads fills up the
processor cache, meaning there is less
cache available for other needs. With
interned strings, a simple object
identi...