Bivariate_LSDsim function

Simulates from the bivariate logarithmic series distribution

Simulates from the bivariate logarithmic series distribution

Bivariate_LSDsim(N, p1, p2)

Arguments

  • N: number of data points to be simulated
  • p1: parameter p1p_1 of the bivariate logarithmic series distribution
  • p2: parameter p2p_2 of the bivariate logarithmic series distribution

Returns

An N×2N \times 2 matrix with NN simulated values from the bivariate logarithmic series distribution

Details

The probability mass function of a random vector X=(X1,X2)X=(X_1,X_2)'

following the bivariate logarithmic series distribution with parameters 0<p1,p2<10<p_1, p_2<1 with p:=p1+p2<1p:=p_1+p_2<1 is given by

P(X1=x1,X2=x2)=Γ(x1+x2)x1!x2!p1x1p2x2(log(1p)), P(X_1=x_1,X_2=x_2)=\frac{\Gamma(x_1+x_2)}{x_1!x_2!}\frac{p_1^{x_1}p_2^{x_2}}{(-\log(1-p))},

for x1,x2=0,1,2,x_1,x_2=0,1,2,\dots such that x1+x2>0x_1+x_2>0. The simulation proceeds in two steps: First, X1X_1

is simulated from the modified logarithmic distribution with parameters p~1=p1/(1p2)\tilde p_1=p_1/(1-p_2) and δ1=log(1p2)/log(1p)\delta_1=\log(1-p_2)/\log(1-p). Then we simulate X2X_2 conditional on X1X_1. We note that X2X1=x1X_2|X_1=x_1 follows the logarithmic series distribution with parameter p2p_2 when x1=0x_1=0, and the negative binomial distribution with parameters (x1,p2)(x_1,p_2) when x1>0x_1>0.

  • Maintainer: Almut E. D. Veraart
  • License: GPL-3
  • Last published: 2021-02-22

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