How to get integrated values from np.array?

Question

I am trying to get integrated values from np.array, list of values. Not the surface under the function, but values. I have values of acceleration and want to get values of velocity. So let's say I have an arry like:

a_x = np.array([111.2, 323.2, 123.3, 99.38, 65.23, -0.19, -34.67])

And I try to get integrated values from this array to get the values of velocity.

If I use lets say simps, quad, trapz, I get the one number (surface).

So how do you integrate np.array values and get integrated values that you can store in a list?

Answer 1

You can't do it by the way you want it, because you didn't understand the process behind it. If you are given acceleration, then using the following equation:

You are able only to find INDEFINITE integral, you know the acceleration, but you don't know starting conditions, thus your solution can't be empty.

As the solution to each of those questions is: "Find velocity given an acceleration", then the solution would be v(t)=integral of a(t)dt+c, where your acceleration is constant, so it doesn't rely on t and it can be written as v(t)=at+c, but still - we don't know anything about how long acceleration lasted and what is the starting condition.

But answering the question about getting values which can be stored in a list - you do it by indexing your values of np.array:

import numpy as np
a_x = np.array([111.2,323.2,123.3])
#Gets first value
print(a_x[0])

If I use lets say simps, quad, trapz, I get the one number (surface).

Because quad,simps,or trapz are methods used for given points, which return value of integral with those given points with corresponding method, for example:

numpy.trapz(y, x=None, dx=1.0, axis=- 1)

if x isn't specified (as in your case), it assumes that you want to use trapeze to estimate the field under the value y of given points with x equal distribution of x. It has to give one value.