program to calculate definite integration

[MaryJ]

HOw do I write a program to calculate definite integration? Please explain

[Messenger]

What is the programming language you are using? If you are using python then I can help you.
You will need to import the scipy module for this and here is an example of this.

>>> import scipy.integrate
>>> func = lambda x: x**2
>>> scipy.integrate.quadrature(func, 0.0, 1.0)
Took 4 points.
(0.333333333333, 0.0)

[garfield1]

Here is the code that can help you

using System;

namespace SimpsonMethod
{
    public class sim
    {
        public static void Main()
        {
            int itr = 100000;
            double x, str, ed, dst, sm = 0, smtt = 0;
            Console.Write("Input range str: ");
            str = double.Parse(Console.ReadLine());
            Console.Write("Input range ed: ");
            ed = double.Parse(Console.ReadLine());
            dst = (ed - str)/itr;
            for (int i = 1; i <= itr; i++)
            {
                x = str + i * dst;
                smtt += f(x - dst / 2);
                if (i < itr)
                {
                    sm += f(x);
                }
            }
            sm = (dst / 6) * (f(str) + f(ed) + 2 * sm + 4 * smtt);
            Console.WriteLine("Value on range [{0}, {1}] is around: {2:0.00000}", str, ed, sm);
        }

        private static double f(double x)
        {
            return x*x+2*x;
        }
    }
}

[MaryJ]

I'm using C... Is there a way to write in in a for loop? I have no clue what I'm doing, an explaination of a program would also be very helpful. Thanks

[garfield1]

This is the logic behind this code.
Here is the for loop

  for (int i = 1; i <= itr; i++)
            {
                x = str + i * dst;
                smtt += f(x - dst / 2);
                if (i < itr)
                {
                    sm += f(x);
                }
            }

You have to just implement the same using c language.

[MaryJ]

alrighty, i'll work on it. thanks