QQ-Plot

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Description

Adjusted QQ-Plot allowing for left-truncated data values.

Usage

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qplot(x, distn, parm, H = NA, plot.it = TRUE, main = "QQ-Plot", 
      xlab = "empirical quantiles", ylab = "theoretical quantiles", ...)

Arguments

x

a numeric vector of data values

distn

character string of the distribution

parm

list of distribution parameters

H

a treshold value

plot.it

logical. TRUE (default) if the result is to be plotted.

xlab, ylab, main

plot labels

...

further graphical parameters

See Also

dplot, cdens

Examples

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set.seed(123)
treshold <- 10
xc  <- rlnorm(100, 2, 2)     # complete sample
xt <- xc[xc >= treshold]     # left truncated sample

# for not assigned treshold the folliwing 
# graphics are identical but not usefull
par(mfrow = c(2,1))
y <- qlnorm(ppoints(length(xt)), 2, 2)
qplot(xt, "plnorm", list(2,2))
qqplot(xt, y); abline(0,1)

# fot trucated data rather use
qplot(xt, "plnorm", list(2,2), H = 10)