actuar (version 1.2-2)

quantile.grouped.data: Quantiles of Grouped Data

Description

Sample quantiles corresponding to the given probabilities for objects of class "grouped.data".

Usage

"quantile"(x, probs = seq(0, 1, 0.25), names = TRUE, ...)

Arguments

x

an object of class "grouped.data".

probs

numeric vector of probabilities with values in $[0, 1]$.

names

logical; if true, the result has a names attribute. Set to FALSE for speedup with many probs.

...

further arguments passed to or from other methods.

Value

A numeric vector, named if names is TRUE.

Details

The quantile function is the inverse of the ogive, that is a linear interpolation of the empirical quantile function.

The equation of the quantile function is $$x = \frac{c_j (F_n(c_{j - 1}) - q) + c_{j - 1} (q - F_n(c_j)}{F_n(c_j) - F_n(c_{j - 1})}$$ for $0

See Also

ogive for the smoothed empirical distribution of which quantile.grouped.data is an inverse; grouped.data to create grouped data objects.

Examples

data(gdental)
quantile(gdental)
Fn <- ogive(gdental)
Fn(quantile(gdental))		# inverse function