python Programming Glossary: sum

Fastest way to list all primes below N in python

http://stackoverflow.com/questions/2068372/fastest-way-to-list-all-primes-below-n-in-python

it works at least for me for some input numbers sum get_primes 2000000 142913828922L #That's the correct sum of.. sum get_primes 2000000 142913828922L #That's the correct sum of all numbers below 2 million 529 in get_primes 1000 False..

What do *args and **kwargs mean? [duplicate]

http://stackoverflow.com/questions/287085/what-do-args-and-kwargs-mean

if you wanted to write a function that returned the sum of all its arguments no matter how many you supply you could.. how many you supply you could write it like this def my_sum args return sum args It 䏭 probably more commonly used in object.. supply you could write it like this def my_sum args return sum args It 䏭 probably more commonly used in object oriented programming..

Python: Once and for all. What does the Star operator mean in Python? [duplicate]

http://stackoverflow.com/questions/2921847/python-once-and-for-all-what-does-the-star-operator-mean-in-python

into positional arguments so you can do this def sum a b return a b values 1 2 s sum values This will unpack the.. so you can do this def sum a b return a b values 1 2 s sum values This will unpack the tuple so that it actually executes.. will unpack the tuple so that it actually executes as s sum 1 2 The double star does the same only using a dictionary and..

Weighted random selection with and without replacement

http://stackoverflow.com/questions/352670/weighted-random-selection-with-and-without-replacement

the alias lookup Normalize the weights such that they sum to 1. a 0.2 b 0.2 c 0.2 d 0.2 e 0.2 This is the probability..

How can you profile a Python script?

http://stackoverflow.com/questions/582336/how-can-you-profile-a-python-script

1 0.000 0.000 0.000 0.000 range 1 0.003 0.003 0.003 0.003 sum EDIT There is a great talk on profiling from PyCon here http..

Why is reading lines from stdin much slower in C++ than Python?

http://stackoverflow.com/questions/9371238/why-is-reading-lines-from-stdin-much-slower-in-c-than-python

that replaces the python for loop BUFFER_SIZE 16384 count sum chunk.count ' n' for chunk in iter partial sys.stdin.read BUFFER_SIZE..

Making a flat list out of list of lists in Python [duplicate]

http://stackoverflow.com/questions/952914/making-a-flat-list-out-of-list-of-lists-in-python

usec per loop python mtimeit s'l 1 2 3 4 5 6 7 8 9 99' 'sum l ' 1000 loops best of 3 969 usec per loop python mtimeit s'l.. the shortcuts based on including the implied use in sum are of necessity O L 2 when there are L sublists as the intermediate.. L 2 times and so on total number of copies is I times the sum of x for x from 1 to L excluded i.e. I L 2 2 . The list comprehension..

Finding moving average from data points in Python

http://stackoverflow.com/questions/11352047/finding-moving-average-from-data-points-in-python

Mathematica it's simple since it's symbolic manipulation Sum i i 0 10 for example but how to calculate sum in python which..

Weighted random sample in python

http://stackoverflow.com/questions/13047806/weighted-random-sample-in-python

encountered. rnd w if rnd 0 return i raise ValueError Sum of weights is not positive to give a categorical distribution..

Order a QuerySet by aggregate field value

http://stackoverflow.com/questions/476017/order-a-queryset-by-aggregate-field-value

def score self return self.vote_set.all .aggregate models.Sum 'value' 'value__sum' class Vote value models.SmallIntegerField.. this Contest.objects.get pk id .image_set.annotate score Sum 'vote__value' .order_by 'score' share improve this answer..

How can I use numpy.correlate to do autocorrelation?

http://stackoverflow.com/questions/643699/how-can-i-use-numpy-correlate-to-do-autocorrelation

of the definition of convolution the correlation C t Sum for inf i inf of a i v t i where inf t inf. Even though this.. positive. That is you were expecting Autocorrelation a Sum for inf i inf a i v t i where 0 t inf But what you got was Autocorrelation.. v t i where 0 t inf But what you got was Autocorrelation a Sum for inf i inf a i v t i where inf t inf What you need to do..

Calculating the percentage of variance measure for k-means?

http://stackoverflow.com/questions/6645895/calculating-the-percentage-of-variance-measure-for-k-means

np.array final_distances .var print print Sum of variances sum cluster_vars print Total Variance points.var.. 1.0 0.427451660041 Cluster 1 0.0 1.0 1.0 1.0 1.0 0.16 Sum of variances 0.587451660041 Total Variance 21.1475 Percent 2.77787757437.. 2.77787757437 On my real dataset does not look right to me Sum of variances 0.0188124746402 Total Variance 0.00313754329764..

How do I calculate r-squared using Python and Numpy?

http://stackoverflow.com/questions/893657/how-do-i-calculate-r-squared-using-python-and-numpy

in a couple of ways the easisest probably being SST Sum i 1..n y_i y_bar ^2 SSReg Sum i 1..n y_ihat y_bar ^2 Rsquared.. easisest probably being SST Sum i 1..n y_i y_bar ^2 SSReg Sum i 1..n y_ihat y_bar ^2 Rsquared SSReg SST Where I use 'y_bar'..