Reading Multidimensional Arrays

Here is a video that demonstrates what is happening during the reading of a 2D array from a file. A nested, implied do loop is used to read the table-like array contained within the file.

Reading 2D Arrays

Recall that each time a Fortran program encounters a READ statement, it moves to a new line, so in order to "read across" the table it is necessary to use an implied do loop (for the inner loop) to avoid having a repeated READ statement.

• Example data

• Example script to read into a two-dimensional array with an implied do loop

        PROGRAM implieddo
        INTEGER row, col
        REAL TEMP(4,3)
  
        OPEN(UNIT=12,FILE='data.dat',STATUS='unknown')
  ! skip first line header
        READ(12,*)
  
        DO row = 1,4
           READ(12,*) ,(TEMP(row,col), col=1,3)
        END DO
  
        PRINT *, TEMP
  
        end
  

• This reads 4 lines of data with 3 data values per line

Video Example