65.96 LengthenedCode

LengthenedCode( C [, i ] )

LengtenedCode returns code C lengthened. C must be a linear code. First, the all-ones vector is added to the generator matrix (see AugmentedCode). If the all-ones vector was already a codeword, nothing happens to the code. Then, the code is extended i times (see ExtendedCode). i is equal to 1 by default. If C was an [n,k] code, the new code generally is a [n+i,k+1] code.

    gap> C1 := CordaroWagnerCode( 5 );
    a linear [5,2,3]2 Cordaro-Wagner code over GF(2)
    gap> C2 := LengthenedCode( C1 );
    a linear [6,3,2]2..3 code, lengtened with 1 column(s) 

ShortenedCode shortens the code, see ShortenedCode. In general, this is not exactly the inverse function.

Previous Up Top Next
Index