Math.rle {rle}

Mathematical functions for rle Objects

Description

Mathematical functions that work independently elementwise on vectors described in Math are implemented for rle objects. See Details for list of exceptions.

Usage

## S3 method for class 'rle'
Math(x, ...)

Arguments

x

An rle object.

...

Additional arguments.

Details

Supported functions include all elements of the S3 Math group excluding the "cumulative" ones, which are not supported at this time and will raise an error. As of this writing, functions supported include (from R help) abs, sign, sqrt, floor, ceiling, trunc, round, signif, exp, log, expm1, log1p, cos, sin, tan, cospi, sinpi, tanpi, acos, asin, atan, cosh, sinh, tanh, acosh, asinh, atanh, lgamma, gamma, digamma, and trigamma.

Functions cumsum, cumprod, cummax, and cummin are not supported at this time and will raise an error.

Value

In every supported case, the call should result in an rle that would have resulted had the call been applied to the original (uncompressed) vector, then compressed using rle. (At no point in the calculation is the uncompressed vector actually constructed, of course.)

By default, the functions do not merge adjacent runs with the same value. This must be done explicitly with compress.rle.

Examples

x <- rle(sample(runif(2), 10, c(.7,.3), replace=TRUE))

stopifnot(isTRUE(all.equal(sin(inverse.rle(x)),inverse.rle(sin(x)))))
stopifnot(inherits(try(cumprod(x)), "try-error"))