Reading columns from data file in fortran

Question

I wrote the following block to read from an external data file:

     open(unit=338,file=\'bounnodes.dat\',form=\'formatted\') 
      DO I=1,NQBOUN
         D         


        

Answer 1

Every read statement in Fortran advances to the next record. This means a new line in normal text files. Try this:

   DO I=1,NQBOUN
     DO J=1,NUMBOUNNODES(I)
        read(338,2001,advance='no') NODEBOUN(i,j)
        write(*,*) 'BOUNDARY NODES',  NODEBOUN(i,j)
     ENDDO
     read(338,*)
   ENDDO

where NQBOUN is number of rows and NUMBOUNNODES(I) is number of columns in a row. (I have allway problems, what is 32x2 vs. 2x32)

You can make it even shorter, using the implied do

   DO I=1,NQBOUN
        read(338,2001) ( NODEBOUN(i,j) , j=1,NUMBOUNNODES(I) )
        write(*,*) ( 'BOUNDARY NODES', NODEBOUN(i,j) , j=1,NUMBOUNNODES(I) )
   ENDDO

or even

   DO I=1,NQBOUN
        read(338,2001) NODEBOUN(i,:)
        write(*,*) 'BOUNDARY NODES',  NODEBOUN(i,1:NUMBOUNNODES(I))
   ENDDO

All of these use Fortran 90 features.