I = x * inv(180);

r = cos (I .* pi);

I = I + 0.5;

r(I == fix (I) & isfinite (I)) = 0;

//=============================================================================

// Copyright (c) 2016-2019 Allan CORNET (Nelson)

//=============================================================================

// LICENCE_BLOCK_BEGIN

// This program is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 2 of the License, or

// (at your option) any later version.

// 

// This program is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

// 

// You should have received a copy of the GNU General Public License

// along with this program.  If not, see .

// LICENCE_BLOCK_END

//=============================================================================

function r = cosd (x)

  I = x * inv(180);

  r = cos (I .* pi);

  I = I + 0.5;

  r(I == fix (I) & isfinite (I)) = 0;

endfunction

//=============================================================================