Data Types

Rabbit
1

Hi! I’m trying to make a calculation, but the answer isn’t right.
It should be 2592788242.73, but get 2592788224.

Here’s the code:

void main()
{
	unsigned long a;
        a = test(37.325, 180.0, -180.0);
}


unsigned long test (double value, double maximum, double minimum)
{
	unsigned long ret;

        if( value > maximum )
            value = maximum;
        if( value < minimum )
            Vavaluelor = minimum;

        ret = ((value - minimum) * 4294967295) / (maximum - minimum);

        return ret;
}

Am I using the wrong data type?

Thanks!

2

You’re losing precision in your constant. Try this:

	double multi;

   multi = 4294967295.0;
   printf("multi = %f
", multi);

I get multi = 4294967290.000000 in the printout.

According to the Dynamic C manual, float and double are both 32-bit values.

3

Environment DC 9.62

Code:
double a;

a=217347.620000;
printf("%f
“,a);
a=2666813.350000;
printf(”%f
“,a);
a=217349.520000;
printf(”%f
“,a);
a=2666813.350000;
printf(”%f
“,a);
a=217350.220000;
printf(”%f
",a);

Result:
217347.625000
2666813.250000
217349.515000
2666813.250000
217350.218000