Simpson's Rule and Numerical Integration

  • Thread starter Nandos
  • Start date
  • #1
6
0
For this problem use Simpson's Rule with N=256 for numerical integration function is y=×^2
and the lower limit is 1 & 3 is the upper limit.

I=[itex]\frac{h}{3}[/itex] {fstart+fend+2Ʃfeven+4Ʃfodd}

Find the numerical integration, using FORTRAN

my solution follows like this:

Program SimpsonRule

IMPLICIT NONE

REAL :: Xmax, Xmin,h , y

INTEGER :: N

Xmax=1.0

Xmin=3.0

N256

contains

h=[itex]\frac{(Xmax-Xmin)}{N}[/itex]

oddweight=4

evenweight=2

DO i=1,256

I=[itex]\frac{h}{3}[/itex] {fstart+fend+2Ʃfeven+4Ʃfodd}


integrate y=x^2

print*,I

END DO

END Program SimpsonRule


comment

I have be told that the code must have subroutine, Do statement, function and call if statement.

my problem most start when i have to tell the computer to sum odd number and multiply by factor of 4 and sum the even number also multiply by factor of two.

the answer for the problem is 8.66667
 
Last edited:

Answers and Replies

  • #2
6
0
the equation BELOW CONTAINS suppose to be : h=(Xmax-Xmin)/N
 
  • #3
SteamKing
Staff Emeritus
Science Advisor
Homework Helper
12,796
1,668
Use CODE tags when entering source code to your post. This helps to preserve any spacing.

In the Loop, you can't just throw your I eqn. from the first part of the post directly into the middle of a loop and expect Fortran to make sense of it. More programming is required to obtain the proper calculation of the integral. How is the program to know what 'fodd' and 'feven' are?
 
  • #4
20,522
4,395
Hi Nandos. Welcome to Physics Forums.

I don't know what this code is that you have written, but it definitely is not FORTRAN. Have you been assigned any simpler problems to work on before you advanced to a program like this?

Chet
 
  • #5
6
0
This is the simpler problem that we need to work on before we do the hard problem, to make problem simple we suppose to find the integration of Y=×2 using Simpson's Rule on FORTRAN
 
  • #6
20,522
4,395
This is the simpler problem that we need to work on before we do the hard problem, to make problem simple we suppose to find the integration of Y=×2 using Simpson's Rule on FORTRAN
Are you saying that this is the first FORTRAN program you will have ever written?

Chet
 
  • #7
6
0
Nope it no but it the first one for integration and Simpsons rule
 
  • #8
20,522
4,395
Nope it no but it the first one for integration and Simpsons rule
So you are familiar with Dimension statements, and have used them before?
 
  • #9
6
0
Yes we have
 
  • #10
20,522
4,395
Yes we have
Then at least the function F should be dimensioned in your FORTRAN program. Do you know how to set up a do loop to carry out a sum on a subscripted variable?
 
  • #11
6
0
Nope i don't know and can you please help me.
 
  • #12
20,522
4,395
Nope i don't know and can you please help me.
You need to get yourself a text book on FORTRAN and do a little studying. The information you need to do this assignment is a little to extensive for a format like PF.
 

Related Threads on Simpson's Rule and Numerical Integration

  • Last Post
Replies
5
Views
3K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
5
Views
824
Replies
2
Views
8K
Replies
1
Views
1K
Replies
9
Views
9K
Replies
5
Views
3K
Replies
10
Views
11K
Replies
7
Views
768
Top