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Optimistic vs. Pessimistic locking
...aid that optimistic locking tends to improve concurrency at the expense of predictability.
Pessimistic locking tends to reduce concurrency, but is more predictable. You pay your money, etc ...
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Combining two Series into a DataFrame in pandas
...to an dataframe then added and additional the additional column by key as 'prediction'. If you need dataframe converted back to a list then use values.tolist()
output=pd.DataFrame(X_test)
output['prediction']=y_pred
list=output.values.tolist()
...
How are virtual functions and vtable implemented?
...and the function called by pointer. In terms of actual performance, branch predictions might have some impact. So for example, if most of your objects refer to the same implementation of a given virtual function, then there is some chance that the branch predictor will correctly predict which functi...
Fitting empirical distribution to theoretical ones with Scipy (Python)?
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# Plot the summary of fitted distributions
dist.plot_summary()
# Make prediction on new datapoints based on the fit
dist.predict(y)
# Retrieve your pvalues with
dist.y_pred
# array(['down', 'none', 'none', 'up', 'up'], dtype='<U4')
dist.y_proba
array([0.02040816, 0.02040816, 0.02040816, 0....
Releasing memory in Python
...hole series of coincidences inside Python and malloc that are very hard to predict.
First, depending on how you're measuring memory, you may only be measuring pages actually mapped into memory. In that case, any time a page gets swapped out by the pager, memory will show up as "freed", even though ...
How do I build a numpy array from a generator?
...take a generator object and turn it into an array unless you either:
can predict how many elements it will yield when run:
my_array = numpy.empty(predict_length())
for i, el in enumerate(gimme()): my_array[i] = el
are willing to store its elements in an intermediate list :
my_array = numpy.arra...
MYSQL OR vs IN performance
...equest to know whether an index is used and which one. It's really hard to predict what the MySQL optimiser will choose.
– Savageman
Mar 20 '10 at 1:16
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How do you set your pythonpath in an already-created virtualenv?
...rather not invoke python to find the site-packages dir, it's at the fairly-predictable path $VIRTUALENV_ROOT/lib/pythonX.Y/site-packages. Docs on .pth files: docs.python.org/3.6/library/site.html
– Alec
Jan 24 '18 at 16:13
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When should I use genetic algorithms as opposed to neural networks? [closed]
...of the brain, and by changing a number of weights between them, attempt to predict outputs based on inputs.
They are two fundamentally different entities, but sometimes the problems they are capable of solving overlap.
sh...
Comparing boxed Long values 127 and 128
...jects and vice versa as needed. The behaviour of autoboxing is not exactly predictable all the time though, as it is not completely specified.
So to be safe and to have predictable results always use .equals() to compare objects and do not rely on autoboxing in this case:
Long num1 = 127, num2 = 1...