Chi Square Distribution

Chi Square Distribution PDF

Chi Square Distribution Chi square variate is a square of a normal variate having 1 degree of freedom and  chi square distribution is a special case of Gamma distribution. If X is following normal distribution N(μ, σ) then Z=((X-μ)/σ)2 is a chi-square variate with 1 degree of freedom. The generalized form of chi-square variate is … Read more Chi Square Distribution

Gamma Function and Gamma Probability Density Function

Gamma Probability Density Function

Gamma function and Gamma Probability Distribution Gamma function and Gamma probability density both are very important concepts in mathematics and statistics. Furthermore, understanding Gamma function and Gamma probability density helps to understand chi-square distribution which plays very important role in machine learning. Especially, in Decision Tree Learning Chi-Square distribution used. In this post, I will … Read more Gamma Function and Gamma Probability Density Function

Expectation in Statistics

Expectation in Statistics

Expectation  in statistics Expectation  in statistics is the weighted average of a random variable with its probability. Suppose you toss three coins, then think of event to turn heads up. Random variable associates number of occurrence of event to its probability. i.e. Expectation of random variable X is denoted by E(X). 1- Expectation of a … Read more Expectation in Statistics

Quadratic Form in Linear Algebra

Matrix of a Quadratic Form in 3 Variables

Quadratic Form in Linear Algebra An expression is called quadratic form in the variables x1, x2, x3,………….,xn over field F. Where aij i=1,2,3,….n, j=1,2,3,….m are elements of F. If aij are real then quadratic form is called real quadratic form. Examples of Quadratic Form 1-x12+x22+ 6 x1 x2 is a quadratic form in variables x1 … Read more Quadratic Form in Linear Algebra

Test for Convergence of Series

Example of Convergence Test

To understand test for  convergence of a series you have to understand sequence and series and related concepts. Sequence A sequence S is a function whose domain is natural numbers and range is real numbers. i.e S: N->R. It is common practice to write a sequence S as Sn Examples of Sequences- Sn = <2n+1> … Read more Test for Convergence of Series

Matrix Representation of a Linear Transformation

Matrix-of-a-Linear-Transformation

Matrix Representation of a Linear Transformation Suppose U and V are two vector spaces over the same field F of dimensions m and n. Let A = {α1, α2, α 3,……,α3} and B={β1, β2, β3,…….,βn} be ordered bases of U and V. If T is a linear transformation such that T:U->V and it is defined … Read more Matrix Representation of a Linear Transformation

Caley-Hamilton Theorem

Caley-Hamilton Theorem

To  understand  Caley-Hamilton theorem you have to know about characteristic polynomial. Characteristic Polynomial If A is a square matrix of of size n * n, and I is identity matrix of the same size as A. Then determinant |A-λI| will result in an equation of the form. Which is called characteristic equation of matrix A … Read more Caley-Hamilton Theorem

Logistic Regression

Logistic Distribution PDF

Hyperbolic Functions These functions are very important in regression, classification and to build neural networks. Moreover, it is important to remember expression hyperbolic functions in the form of exponential functions. I have written the expressions and plotted the functions using python library. Python Codes to Plot Hyperbolic Functions import numpy as np import matplotlib.pyplot as … Read more Logistic Regression