Convert a 2D coordinate into a triangle-based coordinate system for a
    prettier phase diagram.

    Args:
        coordinate: coordinate used in the convex hull computation.

    Returns:
        coordinates in a triangular-based coordinate system.

def triangular_coord(coord):
    """
    Convert a 2D coordinate into a triangle-based coordinate system for a
    prettier phase diagram.

    Args:
        coordinate: coordinate used in the convex hull computation.

    Returns:
        coordinates in a triangular-based coordinate system.
    """
    unitvec = np.array([[1, 0], [0.5, math.sqrt(3) / 2]])
    result = np.dot(np.array(coord), unitvec)
    return result.transpose()