Divide a given range of index into two of exact halves.
Usage
midpoint(x)
Arguments
x
range of index. c(min.index, max.index)
Value
A list of two numeric vectors is returned.
[[1]]
a range of index for the lower half
[[2]]
a range of index for the higher half
Lengths of the two halves are exactly same.
If the parent range has an odd length, the exact center index
is used both at the end of the lower half and at the start of
the higher half.
Details
This function implements the concept of median,
and is used in the midpoints to calculate
quantiles.