rounding array elements

[johnnyjohn20]

Hi,

I have an array with elements filled with values such as 36.0119. I am trying to find a way of rounding each value to the nearest whole number E.G. 36. To show i have attempted this i have used cout with the array and set precision which is ok but i need rounded results in my array. Researching this in books i found functions such as fabs, which is the best i have found. I cannot really show you any code towards this apart from:

a[i] = centervalue+(scalefactor*(sin(pi*a[i]/180)));
a[i] = fabs(a[i]);

cout << a[i]; //using this to check results from fabs function

im sure a rounding function is easy! but i just cannot find it or get one to work!

thanks for looking

[Ancient Dragon]

This is one way to do it.

int main ()
{
   float f = 123.457678F;

   int a = (int)f;
   float b = f - (int)f;
   if(b > 0.5F)
       a++;
   cout << a;
   return 0;
}

[WaltP]

Or, a little easier:

int main ()
{
   float b;
   float f = 123.457678F;

   float b = (int) (f + 0.5);
   cout << b;
   return 0;
}

[johnnyjohn20]

I also have values that need rounding down to get to the nearest like..whole number. Im amazed c++ dosnt have a function that can round to the nearest whole number, regardless of whether it needs rounded up or down.

Thanks for your posts

[Sturm]

Or a little little easier:

int round(const double& c)
{ 
    if (c - (int)c > .5)
        return  (int)c + 1;
    else
        return (int)c;
}

[WaltP]

I also have values that need rounding down to get to the nearest like..whole number. Im amazed c++ dosnt have a function that can round to the nearest whole number, regardless of whether it needs rounded up or down.

Thanks for your posts

The sine of 180is 0. What's the problem?

I also have values that need rounding down to get to the nearest like..whole number. Im amazed c++ dosnt have a function that can round to the nearest whole number, regardless of whether it needs rounded up or down.

Thanks for your posts

Why? It's trivial. Languages don't need a function for every insignificant math concept.