qqnorm(y, ylim, main = "Normal Q-Q Plot", xlab = "Theoretical Quantiles", ylab = "Sample Quantiles", ...) qqline(y, ...) qqplot(x, y, plot.it = TRUE, xlab = deparse(substitute(x)), ylab = deparse(substitute(y)), ...)
qqnorm
produces a normal QQ plot of the values in y
.
qqline
adds a line to a normal quantile-quantile plot which
passes through the quartiles.
Graphical parameters may be given as arguments to qqnorm
,
qqnorm
and qqline
.
ppoints
.
y <- rt(200, df = 5) qqnorm(y); qqline(y, col = 2) qqplot(y, rt(300, df = 5)) data(precip) qqnorm(precip, ylab = "Precipitation [in/yr] for 70 US cities")