problem failure file

[Robert Setif]

   Good morning.

Here is that file with a problem I do not understand.

# dfac.m 21/2/2019  double factorial

function r=dfac(n)

f=1;

if (n=0)

  r=1;

elseif (mod(n,2)=0)

    for i=n:-2:2,f=f*i;,endfor

else

for i=1:2:n,f=f*i;,endfor

  endif

 r=f;

endfunction

Thank you very much.

Best regards

 address@hidden

FRANCE