polyiamonds, an Octave code which considers polyiamonds, simple connected shapes constructed from equilateral triangles connected edgewise.


The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.


polyiamonds is available in a MATLAB version and an Octave version.

Related Data and Programs:


polyominoes, an Octave code which defines, solves, and plots a variety of polyomino tiling problems, which are solved by a direct algebraic approach involving the reduced row echelon form (RREF) of a specific matrix, instead of the more typical brute-force or backtracking methods.


  1. Martin Gardner,
    Mathematical Games: On Polyiamonds: Shapes That are Made Out of Equilateral Triangles, Scientific American,
    Volume 211, December 1964.
  2. T H O'Beirne,
    Pentominoes and Hexiamonds,
    New Scientist,
    Volume 12, pages 379-380, 1961.
  3. Torbijn,
    Journal of Recreational Mathematics,
    Volume 2, pages 216-227, 1969.
  4. Solomon Golomb,
    Polyominoes: Puzzles, Patterns, Problems, and Packings,
    Princeton University Press, 1996,
    ISBN: 9780691024448

Source code:

Last revised on 06 September 2020.