qqplot2: Quantile-Quantile Plots using arbitrary distributions.
In rmngb: Miscellaneous Collection of Functions for Medical Data Analysis

Description Usage Arguments Value Author(s) See Also Examples

Produces a QQ plot of the values in y against the theoretical quantiles of an arbitrary distribution.

1 2	qqplot2(y, fQuant = function(q, x) qnorm(q, mean(x, na.rm = TRUE), sd(x, na.rm = TRUE)), line = TRUE, xlab = "Theoretical Quantiles", ...)

`y`	the data sample.
`fQuant`	a function taking 2 arguments. The first argument is a vector of quantiles, the second is the data sample. This function returns theoretical quantile values.
`line`	logical. Should a line representing perfect fit be plotted?
`xlab`	`xlab` value.
`...`	additional arguments passed to `qqplot`.

Nothing of interest.

Antoine Filipovic Pierucci

qqplot.

y1 <- rnorm(500)
y2 <- rlnorm(500)

# good fit
qqplot2(y1)
# bad fit
qqplot2(y2)

# defining a new fQuant function
fQuant2 <- function(q, x)
    qlnorm(q, mean(log(x)), sd(log(x)))

# better fit
qqplot2(y2, fQuant2)