qqunif {gap}R Documentation

Q-Q plot for uniformly distributed random variable

Description

This function produces Q-Q plot for a random variable following uniform distribution with or without using log-scale.

Usage

qqunif(u,logscale=TRUE,base=10,col=palette()[4],lcol=palette()[2],...)

Arguments

u a vector of uniformly distributed random variables
logscale to use logscale
base the base of the log function
col color for points
lcol color for the diagonal line
... other options as appropriae for the qqplot function

Value

The returned value is a list with components of a qqplot:

x -log(expected value for uniform order statistics)
y -log(observed value)

References

Davison AC. Statistical Models. Cambridge University Press 2003.

Author(s)

Jing Hua Zhao

See Also

mhtplot

Examples

## Not run: 
# Q-Q Plot for 1000 U(0,1) r.v., marking those <= 1e-5
u_obs <- runif(1000)
r <- qqunif(u_obs,pch=21,bg="blue",bty="n")
u_exp <- r$y
hits <- u_exp >= 2.30103
points(r$x[hits],u_exp[hits],pch=21,bg="green")
## End(Not run)

[Package gap version 1.0-17 Index]