static decimal Integrate(decimal down, decimal up, int count, Program.MyFunction f)
{
count *= 2;
var step = (up - down) / (count);
var sum = f(down) + f(up);
for (var i = 1; i <= count - 1; i++)
{
var value = f(down + step * i);
sum += (i % 2 == 0) ? 2 * value : 4 * value;
}
return((step / 3.0m) * sum);
}
static decimal Integrate(decimal down, decimal up, int count, Program.MyFunction f)
{
var step = (up - down) / (count);
var sum = 0m;
for (var i = 0; i <= count - 1; i++)
{
var x1 = down + step * i;
var x2 = down + step * (i + 1);
var value = f((x2 + x1) / 2) * (x2 - x1);
sum += value;
}
return(sum);
}
public static (decimal H, decimal result) CalculateWithAcuracy(decimal down, decimal up, decimal accuracy, Program.MyFunction f)
{
var count = 1;
var lastResult = Integrate(down, up, count, f); //предыдущий
var result = Integrate(down, up, count + 1, f); //текущий
while (Abs(lastResult - result) > accuracy)
{
count++;
lastResult = result;
result = Integrate(down, up, count + 1, f);
}
var H = (up - down) / count;
return(H, result);
}
