ogive {actuar}R Documentation

Ogive for Grouped Data

Description

Compute a smoothed empirical distribution function for grouped data.

Usage

ogive(x, y = NULL, ...)

## S3 method for class 'ogive':
print(x, digits = getOption("digits") - 2, ...)

## S3 method for class 'ogive':
summary(object, ...)

## S3 method for class 'ogive':
knots(Fn, ...)

## S3 method for class 'ogive':
plot(x, main = NULL, xlab = "x", ylab = "F(x)", ...)

Arguments

x an object of class "grouped.data" or a vector of group boundaries in ogive; for the methods, an object of class "ogive", typically.
y a vector of group frequencies; used only if x does not inherit from class "grouped.data".
digits number of significant digits to use, see print.
Fn, object an R object inheriting from "ogive".
main main title.
xlab, ylab labels of x and y axis.
... arguments to be passed to subsequent methods.

Details

The ogive is a linear interpolation of the empirical cumulative distribution function.

The equation of the ogive is

Gn(x) = ((c[j] - x) Fn(c[j-1]) + (x - c[j-1]) Fn(c[j]))/(c[j] - c[j-1])

for c[j-1] < x <= c[j] and where c[0], ..., c[r] are the r + 1 group boundaries and Fn is the empirical distribution function of the sample.

Value

For ogive, a function of class "ogive", inheriting from the "function" class.

Author(s)

Vincent Goulet vincent.goulet@act.ulaval.ca and Mathieu Pigeon

References

Klugman, S. A., Panjer, H. H. and Willmot, G. E. (1998), Loss Models, From Data to Decisions, Wiley.

See Also

grouped.data to create grouped data objects; quantile.grouped.data for the inverse function; approxfun, which is used to compute the ogive; stepfun for related documentation (even though the ogive is not a step function).

Examples

data(gdental)
Fn <- ogive(gdental)
Fn
summary(Fn)
knots(Fn)            # the group boundaries

Fn(knots(Fn))        # true values of the empirical cdf
Fn(c(80, 200, 2000)) # linear interpolations

plot(Fn)

[Package actuar version 1.0-2 Index]