CODEWITHSUNDEEP
pythonnumpynumpy-ndarray
3sm1r
3sm1r

Reputation: 530

Converting an array of time increments to an array of instants

If I have an array of time increments, for example:

intervals = np.random.normal(loc=1,scale=0.1,size=100)

one possible way to create the corresponding array of time instants is to create a list and manually make the sum:

Sum=0.
instants=[]
for k in range(len(intervals)):
    Sum+=intervals[k]
    instants.append(Sum)

instants=np.array(instants)

So, I have just switched from a array of dt(i) to an array of t(i).

But usually python offers elegant alternatives to using for loops. Is there a better way to do it?

Upvotes: 1

Views: 41

Answers (1)

willeM_ Van Onsem
willeM_ Van Onsem

Reputation: 476557

What you here describe is the cumulative sum. You can calculate this with .cumsum() [numpy-doc]:

intervals.cumsum()

For example:

>>> intervals
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>> intervals.cumsum()
array([ 0,  1,  3,  6, 10, 15, 21, 28, 36, 45])

Upvotes: 1

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