Question

Before I begin, I must preface by stating that I am a novice when it comes to FORTRAN. I am maintaining a legacy piece of code from 1978. It’s purpose is to read in some data values from a file, process the values, and then output the processed values to another text file.

Given the following FORTRAN code:

      INTEGER NM,STUBS,I,J,K
      PARAMETER (NM=67,STUBS=43)
      INTEGER*4 MDS(STUBS,NM)

      CALL OPEN$A(A$RDWR,'/home/test/data.txt', MAXPATHLEN,1)
      CALL OPEN$A(A$WRIT,'out',11,2)

      DO 90 I=1,2
          READ(1,82) STUB     
          !-- data processing --!     
          WRITE(2,80) STUB,(MDS(I,J),J=1,24)
90    CONTINUE

80    FORMAT(/1X,A24,25I5)
82    FORMAT(1X,A24,25F5,1)

My question is in regards to the WRITE() statement.

I understand that (2,80) refers to the file output stream opened and pointing to the file 'out' and referenced by the numeral 2. I understand that 80 refers to the format statement referenced by label 80.

STUB is used to store the values read from file input 1. These values are what is processed, and saved into MDS(I,J) in the !-- data processing --! section that I have omitted.

Am I correct in assuming that (MDS(I,J),J=1,24) will write 24 integer values to the output file? In other words, looping from 1 to 24?

Answer 1

Yes, you are correct. The syntax (MDS(I,J), J=1,24) is an “implied DO-loop” and is commonly used in situations like this.