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EvaluationCode -- class of evaluation codes

Description

EvaluationCode is the class of linear codes obtained by evaluating polynomials in $F[X_1,\ldots,X_m]$, where $F$ is a finite field, at a set of points in $F^m$. There are various constructions of evaluation codes depending on how the polynomials and points are chosen. Important examples include Reed-Solomon codes, Reed-Muller codes, monomial codes, Cartesian codes, and toric codes. To construct a linear code, see evaluationCode.

The basic structure is a hash table. One of the values is the resulting linear code of type LinearCode. Other values include the set of points, its vanishing ideal, the set of polynomials, and more.

i1 : F=GF(4);
i2 : R=F[x,y];
i3 : P={{0,0},{1,0},{0,1},{a,a}};
i4 : S={x+y,x^2+y^2, a+x*y^2};
i5 : C=evaluationCode(F,P,S);
i6 : C.VanishingIdeal

                          2              2    2
o6 = ideal (x*y + (a + 1)y  + (a + 1)y, x  + y  + x + y)

o6 : Ideal of R
i7 : C.PolynomialSet

              2    2     2
o7 = {x + y, x  + y , x*y  + a}

o7 : List
i8 : C.LinearCode

                                  4
o8 = LinearCode{AmbientModule => F                                          }
                BaseField => F
                cache => CacheTable{}
                Code => image | 0 0 a   |
                              | 1 1 a   |
                              | 1 1 a   |
                              | 0 0 a+1 |
                GeneratorMatrix => | 0 1 1 0   |
                                   | 0 1 1 0   |
                                   | a a a a+1 |
                Generators => {{0, 1, 1, 0}, {0, 1, 1, 0}, {a, a, a, a + 1}}
                ParityCheckMatrix => | 1 0 0 a+1 |
                                     | 0 1 1 0   |
                ParityCheckRows => {{1, 0, 0, a + 1}, {0, 1, 1, 0}}

o8 : LinearCode
i9 : length C.LinearCode

o9 = 4
i10 : dim C.LinearCode

o10 = 2

Functions and methods returning an object of class EvaluationCode :

For the programmer

The object EvaluationCode is a type, with ancestor classes HashTable < Thing.

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Functions related to ideals and evaluation codes

Symbols that are used as a key for storing information of an evaluation code