5.1.37 farey

Syntax:

farey ( bigint_expression , bigint_expression )
farey ( ideal_expression , bigint_expression )
farey ( module_expression , bigint_expression )
farey ( matrix_expression , bigint_expression )
farey ( smatrix_expression , bigint_expression )
farey ( list_expression , bigint_expression )

Type:

type of the first argument (unless it is list)

Purpose:

lift the first argument modulo the second to the rationals.
The (coefficients of the) result a/b is the best approximation under the condition farey(list(a,b,..),B) is equivalent to list(farey(a,B),farey(b,B),...).

Note:

The current coefficient field must be the rationals.

Example:

ring r=0,x,dp; farey(2,32003); ==> 2