getf SCI/util/testexamples.sci
 
reinit_for_test()
 
%U=mopen('SCI/tests/automatic_tests/macr2tree_data.ref','rb');
 
tree = macr2tree(cosh);
 
txt = tree2code(tree, %T);
 
write(%io(2), txt, '(a)');
function [t] = cosh(z)
//
//  PURPOSE
//     element wise hyperbolic cosinus
//
//  METHOD
//     1/ in the real case use
//
//         cosh(z) = 0.5 (exp(|z|) + exp(-|z|))
//                 = 0.5 ( y + 1/y ) with y = exp(|z|)
//
//         The absolute value avoids the problem of a
//         division by zero arising with the formula
//           "cosh(z) = 0.5 ( y + 1/y ), y=exp(z)"
//         when ieee = 0 for z such that exp(z) equal 0
//         in floating point arithmetic ( approximatly z < -745 )
//
//     2/ in the complex case use :   cosh(z) = cos(i z)
//
if type(z)~=1 then
  error(53,1),
end;
if isreal(z) then
  y = exp(abs(z));
  t = 0.5*(y+10./y)
else
  t = cos(imult(z))
end;
 
endfunction
 
 
xdel_run(winsid());
 
 
mclose(%U);