elephant.kernels.AlphaKernel

class elephant.kernels.AlphaKernel(sigma, invert=False)[source]

Class for alpha kernels.

\[\begin{split}K(t) = \left\{\begin{array}{ll} (1 / \tau^2) \ t\ \exp{(-t / \tau)}, & t > 0 \\ 0, & t \leq 0 \end{array} \right.\end{split}\]

with \(\tau = \sigma / \sqrt{2}\).

Examples

from elephant import kernels
import quantities as pq
import numpy as np
import matplotlib.pyplot as plt

time_array = np.linspace(-1, 4, num=100) * pq.s
kernel = kernels.AlphaKernel(sigma=1*pq.s)
kernel_time = kernel(time_array)
plt.plot(time_array, kernel_time)
plt.title("AlphaKernel with sigma=1s")
plt.xlabel("time, s")
plt.ylabel("kernel, 1/s")
plt.show()

(Source code, png, hires.png, pdf)

../../../_images/elephant-kernels-AlphaKernel-1.png
__init__(sigma, invert=False)

Methods

__init__(sigma[, invert])

boundary_enclosing_area_fraction(fraction)

Calculates the boundary \(b\) so that the integral from \(-b\) to \(b\) encloses a certain fraction of the integral over the complete kernel.

cdf(time)

Cumulative Distribution Function, CDF.

icdf(fraction)

Inverse Cumulative Distribution Function, ICDF, also known as a quantile.

is_symmetric()

True for symmetric kernels and False otherwise (asymmetric kernels).

median_index(times)

Estimates the index of the Median of the kernel.

Attributes

min_cutoff

Half width of the kernel.