Re: casting types

[Dennis Lee Bieber <wlfraed@ix.netcom.com>]

On Tue, 30 Sep 2014 19:56:59 -0700 (PDT), Stribor40 <ikamzic@gmail.com>
declaimed the following:

>ok so i tried truncation attribute and that works just great. Now I want to output this float point to the screen and this is the way i did it....myFunction is myFunction that returns float....
>
>Put(Item=>myFunction,Exp=>0,Aft=>5);
>
>which gives me for example something like this... 0.42997 where without using this function i would get for example  3.23684E-01.....
>

	Unless your function is really corrupting things, I expect the second
to be 4.2997E-01

	Floating point values (in any programming language) do not behave as
"real numbers"... One) they are stored as binary floats, not decimal, so
don't expect exact conversions in/out. Two) they are stored as an exponent,
and a mantissa of the significant binary value -- no 0.00001, rather 1.0E-5
[if I counted correctly].

	So, yes, you do have to control the formatting for display purposes.


	Your original post isn't too clear either...

>I have problem understanding this explicit conversion of types....
>
> var1: FLOAT;
> 
> tmp := Float(x) / 20.0 + Float(y)/ 30.0 + Float(z)/40.0;

	Do these serve any purpose? Neither tmp, x, y, z are declared or
initialized

> return var1 - truncated type of var1
>
>Example if var1 = 123.456 then
>  return  123.456 - 123 
>
>which is 0.123
>
	123.456 - 123 should leave 0.456

>How would I cast var1 to become 123 but still be able to subtract it from var1 and keep float type?
>Is there any other way to do this? 

-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
    wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/