BicopBase.flip

BicopBase.flip()

Raise; override to return the pair with its arguments swapped.

The flipped copula satisfies c'(u1, u2) = c(u2, u1) with the two h-functions (and inverses) exchanged. It is only required for hosting the pair in structure selection (select() reorients selection-time pairs onto their finalized slots with it); evaluation along a fixed structure never calls it.

Returns:

BicopBase

The argument-swapped pair copula — only when a subclass overrides this method.

Raises:

NotImplementedError

Always, unless a subclass provides a native flip.