Question

guys, I’m making simple graph drawer and want to find beautiful values for horizontal lines.
For example, if I have value equals to 72089.601562, beautiful is 70000, or 75000. So, I think that beautifulNumber%5 = 0.
Have you any ideas?

Answer 1

How about this?

#import <math.h>
#import <stdio.h>

#define ROUNDING 5000

int beautify(float input)
{
    // Cast to int, losing the decimal value.
    int value = (int)input;

    value = (value / ROUNDING) * ROUNDING;

    if ((int)input % ROUNDING > ROUNDING / 2 )
    {
        value += ROUNDING;
    }

    return value;
}

int main()
{
    printf("%d\n", beautify(70000.601562)); // 70000
    printf("%d\n", beautify(72089.601562)); // 70000
    printf("%d\n", beautify(76089.601562)); // 75000
    printf("%d\n", beautify(79089.601562)); // 80000
    printf("%d\n", beautify(70000.601562)); // 70000

    return 0;
}