# Fortran- maximum values

1. May 12, 2013

### ShoxPhysics

Hello I am currently working on a program that will take the values from a .csv file containing multiple data and analyzing them. The file can be found here: https://docs.google.com/file/d/0BzuDEPd26OcheVhiWlZ3STlZU0k/edit?usp=sharing The data in question starts in row 11 and is in the first 4 columns. In my program I have labeled these: rvar, ivar1, ivar2, ivar3. Rvar is the value corresponding to a time value in microseconds after start of recording whereas ivar1,ivar2,and ivar3 correspond to the value of the acceleration at that point. I have already calculated the average value of each of these columns.

My question is- how do I find the maximum value for ivar1, ivar2 and ivar3 (separately)?

My current code is below:
Code (Text):
program WSUPhys_csv
implicit none

integer :: stat, num_lines, ivar1, ivar2, ivar3
real :: rvar
character*80 :: line

! open input file
open(10,file='DATA-002.csv',status='old',iostat=stat)
if (stat .ne. 0) then
write(*,*) 'File cannot be opened !'
go to 99
end if

num_lines = 0
do
if (stat .ne. 0) then
go to 99
end if
! skip comment/header lines beginning with ";"
cycle
end if
! read string line into numeric variables
num_lines = num_lines + 1
if (num_lines <=  10) then
write(*,*) num_lines, ':', rvar, ivar1, ivar2, ivar3
end if
Sum_ivar1 = Sum_ivar1 + ABS(ivar1)
Sum_ivar2 = Sum_ivar2 + ABS(ivar2)
Sum_ivar3 = Sum_ivar3 + ABS(ivar3)
Max
end do

! close file
99 continue
Avg_ivar1 = (Sum_ivar1 / num_lines)
Avg_ivar2 = (Sum_ivar2 / num_lines)
Avg_ivar3 = (Sum_ivar3 / num_lines)
close (10)
!
write(*,*) '...done.'
write(*,*) 'Lines processed: ', num_lines
write(*,*) 'Average vertical acceleration', Avg_ivar1/1000
write(*,*) 'Average sideways acceleration', Avg_ivar2/1000
write(*,*) 'Average forward acceleration', Avg_ivar3/1000
end program WSUPhys_csv

2. May 12, 2013

### gsal

The program is named WSUPhys_csv ...is it because you are the same person as WSUPhys from the Tek-Tips Forum? You going around getting other people to do your work? Or are you a class mate and copied all this code from over there?

Either way, at least give a try, this is easy stuff....you can't simply keep asking for help without showing any effort, whatsoever...o.k., you actually can; but most of us forum people don't like it that way.

3. May 12, 2013

### ShoxPhysics

gsal, I apologize. The incorrect version posted, this version is the updated one with Maximum values but I am unsure if I have coded correctly. New code is in blue
Code (Text):
program WSUPhys_csv
implicit none

integer :: stat, num_lines, ivar1, ivar2, ivar3
real :: rvar
character*80 :: line

! open input file
open(10,file='DATA-002.csv',status='old',iostat=stat)
if (stat .ne. 0) then
write(*,*) 'File cannot be opened !'
go to 99
end if

num_lines = 0
do
if (stat .ne. 0) then
go to 99
end if
! skip comment/header lines beginning with ";"
cycle
end if
! read string line into numeric variables
num_lines = num_lines + 1
if (num_lines <=  10) then
write(*,*) num_lines, ':', rvar, ivar1, ivar2, ivar3
end if
Sum_ivar1 = Sum_ivar1 + ABS(ivar1)
Sum_ivar2 = Sum_ivar2 + ABS(ivar2)
Sum_ivar3 = Sum_ivar3 + ABS(ivar3)
[COLOR="Navy"]  MaxVert = MAX(ivar1)
MaxSide = MAX(ivar2)
MaxForward= MAX(ivar3)[/COLOR]
end do

! close file
99 continue
Avg_ivar1 = (Sum_ivar1 / num_lines)
Avg_ivar2 = (Sum_ivar2 / num_lines)
Avg_ivar3 = (Sum_ivar3 / num_lines)
close (10)
!
write(*,*) '...done.'
write(*,*) 'Lines processed: ', num_lines
write(*,*) 'Average vertical acceleration', Avg_ivar1/1000
write(*,*) 'Average sideways acceleration', Avg_ivar2/1000
write(*,*) 'Average forwards acceleration', Avg_ivar3/1000
[COLOR="Navy"]write(*,*) 'Maximum vertical acceleration', MaxVert
write(*,*) 'Maximum sideways acceleration', MaxSide
write(*,*) 'Maximum forward acceleration',  MaxForward[/COLOR]

end program WSUPhys_csv

Last edited by a moderator: May 12, 2013
4. May 12, 2013

### gsal

Your ivar1, ivar2, ivar3 variables are NOT arrays, they are scalars and they contain the value just read. So, it does not make sense to apply the 'max()' function to them.

You need initialize your Max* variables to zero before you go into the loop; then, inside the loop, you need to compare the ivar* value just read to the one stored in the corresponding Max* variable and keep the largest of the two.

5. May 12, 2013

### ShoxPhysics

So do I create a separate do loop?

something like this:

Code (Text):
Do i=1,72000
If (ivar1 >> ivar1) then
MaxVert=ivar1
or am I way off track?

6. May 12, 2013

### gsal

Within the same loop

Code (Text):

If (ivar1 > MaxVert) then
MaxVert=ivar1
end if

7. May 12, 2013

Thank you!