Re: Numerical calculations: Why not use fixed point types for everything?

[Ada novice <shai.lesh@gmx.com>]

On Saturday, February 2, 2013 10:08:50 PM UTC+1, Nasser M. Abbasi wrote:

> 
> Well, it is common only in sloppy programming.
> 
> 
> 
> loop counters should always be discrete. as in integers,
> 

I do not think we should judge things too quickly. By having a "delta" that we can explicitly specify, this can make the code simpler to understand. Look at this code:

with Ada.Text_IO;             use Ada.Text_IO;
with Ada.Long_Float_Text_IO;  use Ada.Long_Float_Text_IO;

procedure Step_Freq is
   Count : Integer;
   Frequency : Long_Float;
   Frequency_Start : constant := -44.88;
   Frequency_Step  : constant := (67.32 - Frequency_Start) / 299.0;
   Delta_Frequency : Long_Float;

 begin
   Count := 0;
   Frequency := Frequency_Start;
   for I in 1..300 loop
       Frequency := Frequency_Start + Frequency_Step * Long_Float (I - 1);
       if I = 2 then
          Delta_Frequency := abs(Frequency - Frequency_Start);
          Put (Item => Delta_Frequency, Fore => 3, Aft => 5, Exp => 0); Put("  ");
          Put (Item => Frequency_Step, Fore => 3, Aft => 5, Exp => 0);
          New_Line;
       end if;
       Count := Count + 1;
   end loop;
    Put_Line ("Count after loop is" & Integer'Image (Count));
    New_Line;
    Put (Item => Frequency, Fore => 3, Aft => 3, Exp => 0);
end Step_Freq;

Well, I am using a discrete loop counter. But is this the best way to go about for such a simple example? What if I want the Frequency_Step to take a specific value? Then I will have perhaps to play with the range and the amount of discrete points I need in order to arrive at a desired Frequency_Step in the code. So why not use fixed-point for the frequency as we know exactly what step we want?

Thanks.
YC