# demonstrates the concept of variance using scatter plots population.size = 1000000 population.mean1x = 0 population.mean1y = 0 population.std1x = 50 population.std1y = 50 population.mean2x = 0 population.mean2y = 0 population.std2x = 500 population.std2y = 500 sample.size = 10000 axis.limit = 5000 population.data1x = rnorm(population.size,population.mean1x,population.std1x) population.data1y = rnorm(population.size,population.mean1y,population.std1y) population.data2x = rnorm(population.size,population.mean2x,population.std2x) population.data2y = rnorm(population.size,population.mean2y,population.std2y) population.mean = mean(population.data) par(mfrow=c(2, 1)) par(mar=c(1,1,1,1)) sample.data1x = sample(population.data1x,sample.size,replace = TRUE) sample.data1y = sample(population.data1y,sample.size,replace = TRUE) sample.data2x = sample(population.data2x,sample.size,replace = TRUE) sample.data2y = sample(population.data2y,sample.size,replace = TRUE) plot(sample.data1x,sample.data1y,xlim = c(-axis.limit,axis.limit),,ylim = c(-axis.limit,axis.limit)) plot(sample.data2x,sample.data2y,xlim = c(-axis.limit,axis.limit),,ylim = c(-axis.limit,axis.limit))