`scipy.integrate._quadrature:cumulative_trapezoid`

Signature

def cumulative_trapezoid(y, x = None, dx = 1.0, axis = -1, initial = None)

Cumulatively integrate y(x) using the composite trapezoidal rule.

y : array_like: Values to integrate.
x : array_like, optional: The coordinate to integrate along. If None (default), use spacing dx between consecutive elements in y.
dx : float, optional: Spacing between elements of y. Only used if x is None.
axis : int, optional: Specifies the axis to cumulate. Default is -1 (last axis).
initial : scalar, optional: If given, insert this value at the beginning of the returned result. 0 or None are the only values accepted. Default is None, which means res has one element less than y along the axis of integration.

res : ndarray: The result of cumulative integration of y along axis. If initial is None, the shape is such that the axis of integration has one less value than y. If initial is given, the shape is equal to that of y.

from scipy import integrate
import numpy as np
import matplotlib.pyplot as plt

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x = np.linspace(-2, 2, num=20)
y = x
y_int = integrate.cumulative_trapezoid(y, x, initial=0)

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plt.plot(x, y_int, 'ro', x, y[0] + 0.5 * x**2, 'b-')

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[<matplotlib.lines.Line2D object at 0x7f3f68269940>, <matplotlib.lines.Line2D object at 0x7f3f68268440>]

plt.show()

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