ata {ChainLadder}  R Documentation 
Calculate AgetoAge Factors
Description
Calculate the matrix of agetoage factors
(also called "reporttoreport" factors, or "link ratios")
for an object of class triangle
.
Usage
ata(Triangle, NArow.rm = TRUE, colname.sep = "",
colname.order=c("ascending","descending"))
Arguments
Triangle 
a loss "triangle". Must be a 
NArow.rm 

colname.sep 
a 
colname.order 
"ascending" indicates that the less mature age comes first in the column labels of the ata matrix 
Details
ata
constructs a matrix of agetoage (ata) factors resulting
from a loss "triangle" or a matrix
.
Simple averages and volume weighted averages are saved as
"smpl" and "vwtd" attributes, respectively.
Value
A matrix
with "smpl" and "vwtd" attributes.
Author(s)
Daniel Murphy
See Also
summary.ata
, print.ata
and chainladder
Examples
ata(GenIns)
# Volume weighted average agetoage factor of the "RAA" data
y < attr(ata(RAA), "vwtd")
y
# "To ultimate" factors with a 10% tail
y < rev(cumprod(rev(c(y, 1.1))))
names(y) < paste(colnames(RAA), "Ult", sep="")
y
## Label the development columns in "ratiotype" format
ata(RAA, colname.sep=":", colname.order="desc")