MuPAD Pro Computing Essentials - Examples 

Example 10.2 - Two simple procedures to convert between radians and degrees

deg := proc(x)

begin
   if is(x, Type::Real) then
      return(x*180/PI)
   else
      return(procname(args()))
   end;
end:

rad := proc(x)

begin
   if is(x, Type::Real) then
      return(x*PI/180)
   else
      return(procname(args()))
   end;
end:

    
deg(1);

deg(PI);

180

rad(180);

float(rad(1));

0.01745329252