Coding for table problem re. slade 1

[coboldummy]

slade and other members

This is the code I have produced so far for my problem with cobol tables.

FD Student-File.
01 Student-Rec.
03 SF-CandNo Pic 99.
03 SF-Paper1-Mark Pic 999.
03 SF-Paper2-Mark Pic 999.
03 SF-Paper3-Mark Pic 999.

Working-Storage Section.
01 W-Student-EOF Pic X Value "N".
88 End-Of-Student-File Value "Y".

01 W-ExamTable.
03 W-Paper Occurs 3.
05 W-Mark Pic 999 Occurs 4.

Procedure Division.

Open Input Student-File
Move Zeros to W-ExamTable
Read Student-File
At End Move "Y" to W-Student-EOF
Not At End
Perform Paper1
Perform Paper2
Perform Paper3
End-Read.

Paper1.
Evaluate SF-Paper1-Mark
When SF-Paper1-Mark < 40
Add 1 to W-ExamTable(1,1)
When SF-Paper1-Mark > 39 AND < 50
Add 1 to W-ExamTable(1,2)
When SF-Paper1-Mark > 49 AND < 70
Add 1 to W-Examtable(1,3)
When SF-Paper1-Mark > 69
Add 1 to W-ExamTable(1,4)
End-Evaluate.

Ive got this far but I am sure I am not tackling the problem the right way. I think the Perform Varying should prehaps be used but dont know how to go about it.
Any help would be gratefully appreciated.

 

[slade]

Hi CD,

Don't think you're on the right track. Let's take a look at your i/p file:

file
students
papers

What this says is: to process the file you have to process all the students in the file. To process a student you must process all the papers for the student.

This gives you insight into what control breaks you will need. Note, this approach can be used for a vast majority of batch (and some on-line) problems you'll be faced with in your career.

So from this you can construct a first-cut mainline that looks like this (written in pseudo code):

       1000-mainline.
           perf 8000-init
           perf 7000-1st-read
           if eof perf 9999-bad-term stop.
           perf 2000-proc-all-students until eof
           perf 6000-print-grade-summary
           perf 9000-good-term stop 
           .
       2000-proc-all-students.
           perf 3000-proc-all-grades-for-student
                until student-is-finished
           .

       3000-proc-all-grades-for-student.
           perf 3100-determ-grade-title
           perf 7100-get-nxt-ip-rec
           .
       3100-determ-grade-title.
      *===> here's where your table processing is done.
      *===> give it a try and let me know what you come up
      *===> with. Hint: its a 2 dimen table.

Other ques you can ask yourself: Why do I do that 1st read outside the loop? How do I determine when student-is-finished? What happens if P# 2000- is left as written? Why do I need P# 2000-; it doesn't do anything?  This approach may confuse you at first, but stay with it; it's worth the  effort.

Regards, Jack.

 

[coboldummy]

Cheers Jack thats helped me a bit. I'll give it a go.

CobolDummy.