Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

Defining a white noise process in Python

Tags:

I need to draw samples from a white noise process in order to implement a particular integral numerically.

How do I generate this with Python (i.e., numpy, scipy, etc.)?

like image 816
dbliss Avatar asked Aug 26 '15 22:08

dbliss


People also ask

What is a white noise process?

A white noise process is a random process of random variables that are uncorrelated, have mean zero, and a finite variance. Formally, X(t) is a white noise process if E(X(t))=0,E(X(t)2)=S2, and E(X(t)X(h))=0 for t≠h.

How do you forecast white noise?

All Answers (11) A white noise process, by definition, cannot be predicted. 1) If a process is really white noise then it is not forecastable by definition (because its values at different times are statistically independent). 2) By far not all processes in the world are forecastable.

What is white noise time series in Python?

In this tutorial, you discovered white noise time series in Python. White noise time series is defined by a zero mean, constant variance, and zero correlation. If your time series is white noise, it cannot be predicted, and if your forecast residuals are not white noise, you may be able to improve your model.

How to get white noise from a NumPy array?

"numpy.random.uniform(low=0.0, high=1.0, size=1000)", "np.random.triangular(-3, 0, 8, 100000)" will also get white noise. You can also have a correlated signal process and randomize it using "numpy.random.shuffle" for getting white noise.

What is white noise in regression analysis?

White noise are variations in your data that cannot be explained by any regression model. And yet, there happens to be a statistical model for white noise. It goes like this for time series data: The observed value Y_i at time step i is the sum of the current level L_i and a random component N_i around the current level.

What is white noise in time series forecasting?

White noise is an important concept in time series forecasting. If a time series is white noise, it is a sequence of random numbers and cannot be predicted. If the series of forecast errors are not white noise, it suggests improvements could be made to the predictive model. In this tutorial, you will discover white noise time series with Python.


1 Answers

You can achieve this through the numpy.random.normal function, which draws a given number of samples from a Gaussian distribution.

import numpy import matplotlib.pyplot as plt  mean = 0 std = 1  num_samples = 1000 samples = numpy.random.normal(mean, std, size=num_samples)  plt.plot(samples) plt.show() 

1000 random samples drawn from a Gaussian distribution of mean=0, std=1

like image 170
Sam Avatar answered Sep 20 '22 13:09

Sam