I am having trouble with my code. My goal is to calculate the average of 5 different columns of data. Problem is, in the data file every 4000 lines or so there is a comment beginning with #. I need to read each of these lines into a character string, so that my code will not read them as numbers to be added. I am doing this as a research project for my university and was instructed to use Fortran 77 without arrays. Here is my code:
program mean_analysis
implicit none
integer i
integer N
double precision a, b, c, d, e
double precision sumb
double precision sumc
double precision sumd
double precision suma
double precision sume
character(100) event
sumb = 0
sumc = 0
sumd = 0
suma = 0
sume = 0
N=40010
open(unit = 7, file="zpc_initial_momenta.dat")
do i=1, 1
read(7,'(A)') event
end do
do i=4002, 4002
read(7,'(A)') event
end do
do i=8003, 8003
read(7,'(A)') event
end do
do i=12004, 12004
read(7,'(A)') event
end do
do i=16005, 16005
read(7,'(A)') event
end do
do i=20006, 20006
read(7,'(A)') event
end do
do i=24007, 24007
read(7,'(A)') event
end do
do i=28008, 28008
read(7,'(A)') event
end do
do i=32009, 32009
read(7,'(A)') event
end do
do i=36010, 36010
read(7,'(A)') event
end do
do i=1, N
read(7,*) a, b, c, d, e
write(7, *) event
suma = suma+a
sumb = sumb+b
sumc = sumc+c
sumd = sumd+d
sume = sume+e
end do
close(7)
open(unit = 8, file="outputanalysis.dat")
write(8,*) suma/N, sumb/N, sumc/N, sumd/N, sume/N
close(8)
end program
The issue is when I run this code, there is a runtime error. The code still thinks that each event (at the lines provided) is a number and attempts to add it into the sum for each column
(Bad real number in item 1 of list input) [there is a # on the first line in the data file]). I want the program to essentially ignore each row beginning with a #.
Can someone fill me in on what I'm doing wrong, or suggestions on what to include? I am new to Fortran, so anything too advanced might go over my head.
I tried putting each "event" (rows beginning with #) into a character string so that they would not be read as a number. The program still thinks they are numbers to be added.
You're looking for Fortran's internal read capability. First, read a line from the file, then determine if it is a comment or needs to be parsed for values. Here's a quick hack. You should probably include error handling if a read fails.
program mean_analysis
implicit none
integer i, n
double precision a(5), s(5)
character(100) event
s = 0
n = 0
open(unit = 7, file="zpc_initial_momenta.dat")
do
read(7,'(A)',end=10) event
event = adjustl(event)
if (event(1:1) == '#') cycle ! Skip comment lines
read(event,*) a
s = s + a
n = n + 1
end do
10 close(7)
open(unit = 8, file="outputanalysis.dat")
write(8,*) s / n
close(8)
end program
Edited: Seems you should make an appointment with the department chair or dean or provost. Forcing you to use a 46 year old dialect of a language is not preparing you for the future. If your prof insists on F77, then at least have some fun (although I doubt he'll look at the code).
INTEGER I, N
DOUBLE PRECISION A,B,C,D,E,SA,SB,SC,SD,SE
DATA SA,SB,SC,SD,SE,N/5*0,0/
COMMON SA, A
OPEN(UNIT=7,FILE="zpc_initial_momenta.dat")
1000 READ(7,*,ERR=1000,END=100) A,B,C,D,E
CALL SA AND A
SB=S B + B
S C =SC + C
SD =D + S D
CALLADDE(S E, E)
N = N + 1
GOTO 1000
1 0 0 CONTINUE
CLOSE(7)
OPEN(UNIT=8,FILE="outputanalysis.dat")
WRITE(8,*) SA/N, S B/N, S C / N, SD/ N, SE/N
CLOSE(8)
END
SUBROUTINE ADD E(S, X)
DOUBLEPRECISION S,X
DOUBLE PRECISION C,T,Y
DATA C /0/
Y = X - C
T = S + Y
C = (T - S) - Y
S = T
END
SUBROUTINE SA AND A
DOUBLE PRECISION SS,TT
COMMON SS,TT
SS = SS + TT
END