R Statistics Cookbook

How to do it...

In this recipe we will first generate some Gaussian numbers and then, using the pnorm() and qnorm() functions, we will calculate the area to the left and to the right of x=2, and get the 90th quantile to plot the density.

1. Generate 10000 Gaussian random numbers:

vals = rnorm(10000,0,1)

2. Plot the density and draw a red line at x=2:

plot(density(vals))abline(v=2,col="red")

3. Calculate the area to the left and to the right of x=2, using the pnorm() function and use the qnorm() quantile function to get the 97.7th quantile:

print(paste("Area to the left of x=2",pnorm(2,0,1)))print(paste("Area to the right of x=2",1-pnorm(2,0,1)))print(paste("90th Quantile: x value that has 97.72% to the left",qnorm(0.9772,0,1)))

After running ...