Duadic and triadic codes over a finite non-chain ring and their Gray images

Let f(u) be a polynomial of degree m, m ≥ 2, which splits into distinct linear factors over a finite field 𝔽q. Let 𝓡 = 𝔽q[u] / ⟨ f(u) ⟩ be a finite non-chain ring. In this paper, we study duadic codes, their extensions and triadic codes over the ring 𝓡. A Gray map from 𝓡n to (𝔽q m)n is defined which preserves self-duality of linear codes. As a consequence, self-dual, isodual, self-orthogonal and complementary dual(LCD) codes over 𝔽 q are constructed. Some examples are also given to illustrate this.