LinearAlgebra[Modular]
MatGcd
compute mod m GCD from Matrix of coefficients
Calling Sequence
Parameters
Description
Examples
MatGcd(m, A, nrow)
m
-
modulus
A
mod m Matrix; each row stores the coefficients of a polynomial
nrow
number of rows in A containing polynomial coefficients
The MatGcd function computes the GCD of the nrow polynomials formed by multiplication of the input Matrix A by the Vector . It is capable of computing the mod m GCD of more than two polynomials simultaneously.
Each polynomial must be stored in a row of the input Matrix, in order of increasing degree for the columns. For example, the polynomial is stored in a row as [3, 2, 1].
On successful completion, the degree of the GCD is returned, and the coefficients of the GCD are returned in the first row of A.
Note: The returned GCD is not normalized to the leading coefficient 1, as the leading coefficient is required for some modular reconstruction techniques.
This command is part of the LinearAlgebra[Modular] package, so it can be used in the form MatGcd(..) only after executing the command with(LinearAlgebra[Modular]). However, it can always be used in the form LinearAlgebra[Modular][MatGcd](..).
An example of three polynomials with a known GCD.
An example of a trivial GCD.
See Also
coeff
Expand
LinearAlgebra/Details
LinearAlgebra[Modular][Mod]
randpoly
seq
trunc
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