futile.any (version 1.3.2)

anylength: Get the generic length of an object

Description

This function consolidates size dimensions for one and two dimensional data structures. The idea is that many operations require knowing either how long a vector is or how many rows are in a matrix. So rather than switching between length and nrow, anylength provides the appropriate polymorphism to return the proper value.

Usage

anylength(...)

Arguments

...

Abstract function controlled by lambda.r

Value

The length or nrow of the object

Details

anylength(data) data - An object

When working with libraries, it is easy to forget the return type of a function, particularly when there are a lot of switches between vectors, matrices, and other data structures. This function along with its anynames counterpart provides a single interface for accessing this information across objects.

The core assumption is that in most cases length is semantically synonomous with nrow such that the number of columns in two-dimensional structures is less consequential than the number of rows. This is particularly true of time-based objects, such as zoo or xts where the number of observations is equal to the number of rows in the structure.

See Also

anynames

Examples

  m <- matrix(c(1,2,3,4,5,6), ncol=2)
  anylength(m)

  v <- c(1,2,3,4,5)
  anylength(v)