CODEWITHSUNDEEP
rrandom
user2064900
user2064900

Reputation: 21

How do I create random (x,y) points having a Gaussian distribution?

I need to create a set of 100 random (x,y) points in R that are Gaussian. How do I do this?

Upvotes: 2

Views: 179

Answers (1)

Jilber Urbina
Jilber Urbina

Reputation: 61154

Take a look at mvrnorm function from MASS package

library(MASS)
Sigma <- matrix(c(10,3,3,2),2,2)  # Covariance Matrix
set.seed(1)  # For the example to be reproducible
Random_XY <- mvrnorm(n=100, c(0, 0), Sigma) # Random (x,y) from a Gaussian distr.
head(Random_XY) 

           [,1]       [,2]
[1,]  2.3299984 -0.4196921
[2,] -0.2261965 -1.2474779
[3,]  2.3538800  1.7025069
[4,] -4.9527947 -1.8730622
[5,] -1.0148272 -0.4114252
[6,]  2.0557678  2.4378417

EDIT

Since a gaussian process has mean 0 and variance 1 and zero correlation, the correct answer should be:

mvrnorm(n=100, c(0, 0), diag(c(1,1)))

Where the vector of means is c(0,0) and a unitary covariance matrix diag(c(1,1))

As @Ben Bolker pointed out, the fastest way to go (using R Base function) is:

data.frame(x=rnorm(100),y=rnorm(100))

Upvotes: 5

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