 [Help: CAS Code] Comparing exact with approx expressions - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: HP Prime (/forum-5.html) +--- Thread: [Help: CAS Code] Comparing exact with approx expressions (/thread-7173.html) [Help: CAS Code] Comparing exact with approx expressions - compsystems - 11-05-2016 02:57 PM I want to print in the terminal window, a numeric or symbolic value, depending on whether, is the same or different in their approximate or exact value, to avoid print two the same result. For this I am writing a program that compares two expressions exactSameApprox(expr1, expr2) PHP Code: `#cas  exactSameApprox(expr1, expr2):=  begin    //print(delDot(expr1) == delDot(expr2)); wait();    if eq(delDot(expr1),delDot(expr2)) == true then      return true;    else      return false;    end;  end;  delDot( mExpr ):=  begin    local exprStr := string( mExpr );     if fp( approx( mExpr ) ) == 0 then      exprStr:= left(exprStr, instring(exprStr,".")-1); // the decimal dot is deleted when the fractional part is zero    end;    return exprStr;  end;#end ` terms 1: If the approximate value is the same that exact return "TRUE" exactSameApprox(5, 5) -> true "5" same "5" -> true numbers with fractional part == 0, are considered equals, it requires a function to remove the fractional part delDot( mExpr ) exactSameApprox(1, 1.0) -> true or exactSameApprox(1, 1.) -> true or exactSameApprox(1.0, 1) -> true or 1.0 -> 1 "1" same "1" -> true 2: if the exact value is different from the approximate value must be return FALSE, BUT MY CODE FAILS. exactSameApprox(2, 4/2) -> true // FAIL =( must be return FALSE "2" same "4/2" -> false Who can help me improve the code above? the problem is that when storing, or convert to string a mathematical expression, this first is evaluated. Using QUOTE (not to recall the argument of the input arg) to convert string =( PHP Code: `deldot(mexpr):=beginlocal exprstr:= string( quote(mexpr) ); // -> exprstr:=" 'mexpr' " and not 'rcl(mexpr)', ` Thanks RE: [Help: CAS Code] Comparing exact with approx expressions - compsystems - 11-05-2016 08:39 PM sorry for my bad English expr0:=4/2 [enter] 2 ok string(expr0) [enter] "2" ok expr1:=quote(4/2) [enter] 4/2 ok string(expr1) [enter] "2" =( I want to display as "4/2" now string(eval(var1,1)) [enter] "4/2" ok =) but within a program, how I make so that the entry is stored as quote? PHP Code: `compare1(expr1, expr2):=begin  local str1:= string(eval(expr1,1));  local str2:= string(eval(expr2,1));  local rtn;  print();  print(str1); wait();  print(str2); wait();  if eq(str1,str2) then      rtn:= true;  else      rtn:= false;  end;  print(rtn); wait();  return rtn;end; ` compare1(2,4/2) true =( compare1('2','4/2') false =) but forcing the entry as '' the idea is that the program will become '' I think that an object between single quotes '' must be stored as such and not evaluate it, otherwise the QUOTE command has not purpose, are you agree? expr2:='4/2' type(expr2) -> DOM_QUOTEDEXPR // without evaluate RE: [Help: CAS Code] Comparing exact with approx expressions - CH3791 - 11-05-2016 11:27 PM (11-05-2016 08:39 PM)compsystems Wrote:  I think that an object between single quotes '' must be stored as such and not evaluate it, otherwise the QUOTE command has not purpose, are you agree? This is a very good proposal. However, one thing I don't understand is your use of two arguments for the eval command eg. string(eval(expr1,1)). None of the documentation or manuals state anything about what a second argument will do. EDIT: Oops, I see you've already discussed it here. http://www.hpmuseum.org/forum/thread-7162.html