modular_linear_solver SciMax Toolbox moebius

SciMax Toolbox >> modulus

modulus

Option variable

modulus

Description

Default value: false

When modulus is a positive number p, operations on rational numbers (as returned by rat and related functions) are carried out modulo p, using the so-called "balanced" modulus system in which n modulo p is defined as an integer k in [-(p-1)/2, ..., 0, ..., (p-1)/2] when p is odd, or [-(p/2 - 1), ..., 0, ...., p/2] when p is even, such that a p + k equals n for some integer a.

If expr is already in canonical rational expression (CRE) form when modulus is reset, then you may need to re-rat expr, e.g., expr: rat (ratdisrep (expr)), in order to get correct results.

Typically modulus is set to a prime number. If modulus is set to a positive non-prime integer, this setting is accepted, but a warning message is displayed. Maxima will allow zero or a negative integer to be assigned to modulus, although it is not clear if that has any useful consequences.

modular_linear_solver SciMax Toolbox moebius