Path: utzoo!utgpu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!ria!braille.uwo.ca!bill
From: bill@braille.uwo.ca (Bill Carss)
Newsgroups: comp.sys.apple2
Subject: Help with Floats in Hyper C
Summary: Explanation of how to use floats in Hyper C wanted.
Keywords: float, EXTENDED, invalid expression
Message-ID: <.677021512@braille.uwo.ca>
Date: 15 Jun 91 21:31:52 GMT
Sender: news@ria.ccs.uwo.ca
Distribution: na
Lines: 54


I am just beginning to learn C.  I am using K&R and have FINALLY started
to work my way through the text as I learn the language.  The float 
problem cropped up in the thrid program discussed.  It is simply a 
program to convert fahrenheit temperatures to celsius and to get a little
more accuracy than int's provide, they suggest declaring fahr and celsius
as ftype float.

The program is as follows:

#include <stdio.h>  /* I changed the name of std.h for compatability */
#include <fp.h>

/*  Convert Fahrenheit to celsius in the range
    0, 20, ..., 300                             */

main()
  {
    float fahr, celsius;
    int lower, upper, step;

    lower = 0;
    upper = 300;
    step = 20;
 
    fahr = lower;
    while (fahr <= upper)  {
       celsius = (5.0/9.0) * (fahr-32);
       printf("%3.0f %6.1f \n, fahr, celsius");
       fahr = fahr + step;
    }
 }

I typed in the above program and got an error message telling me that the 
"fahr = lower;" line was not a pointer.

I have a friend is is an experienced C programmer (he has a couple of 
commercial packages to his name) and he suggested casting <?> in the form

fahr = (float)lower;

This resulted in an error message relating to the while statement such that
it was invalid.

I have done some reading of the documentation that I have and have found
nothing much to do with "float"s other than the fact that they are not ever
defined (that I can find) and it is necessary to convert them to other
things to use them.  There are functions like cvxtoi (and the 
reverse), but I thought PPF should take care of that for me.

Any halp anyone can give me would be greatly appreciated.
-- 
Bill Carss
bill@braille.uwo.ca