invert {hash}

Create an inverted hash.

Description

THIS IS AN EXPERIMENTAL FUNCTION. THE IMPLEMENTATION OR INTERFACE MAY CHANGE WITHOUT WARNING.

Invert creates an inverted hash from an existing hash. An inverted hash is one in which the keys and values are exchanged.

Usage

invert(x)
inverted.hash(...)

Arguments

x

A hash object

...

Arguments passed to the hash function.

Details

For invert, keys and value elements switch. Each element of the values(x) is coerced to a key. The value becomes the associated key.

For inverted.hash, a hash is created than inverted. It is defined as:

function(...) invert(hash(...))

Value

A hash object with: keys as the unique elements of values(x) and values as the associated keys{x}

Author(s)

Christopher Brown

See Also

See also link{hash} and make.keys

Examples

  h <- hash( a=1, b=1:2, c=1:3 )
  invert(h)

  inverted.hash( a=1, b=1:2, c=1:3 )