Re: [ferret_users] Reading fortran stream file

[Jaison Kurian <jaison@xxxxxxxxxxxxxxxxxx>]

Hi Imran & Dan,
                 We can write both the variable to a single
binary file and read it properly using the same jnl file
provided the two variables are written as two 'records'.

 About "recl" (ie record length) : For a gridded data it
should be "xpoints*ypoints*4". Each variable,level & time
will increment the "rec" (ie, record) by 1. So in Imrans's 
example recl should not be 16 but 8*5*4 as noted by Dan.

 I didn't explore the binary file writing for multiple
variables with multiple time/levels. But it seems Ferret
needs the binary file without mixing variables...but
in appended form (all the values for one variable, then
the next variable ..like that). You can try it out.

 In order to write myvar1 and myvar2 to a single binary
file, please proceed as follows (you can use the same jnl
file for reading it in Ferret)

------------------------------------------------------------------
      REAL myvar1(8,5),myvar2(8,5)

      open (unit=20, file="test.dat", access="direct", recl=8*5*4)

      do i = 1, 8
         do j=1, 5
            myvar1(i,j)= Real(i) + Real(j) * 10.0
            myvar2(i,j)=-(Real(i) + Real(j) * 10.0)
         enddo
      enddo

      write (20,rec=1) ((myvar1(i,j), i=1,8),j=1,5)
      write (20,rec=2) ((myvar2(i,j), i=1,8),j=1,5)

      end
------------------------------------------------------------------
Regards,

Jaison

On Thu, 6 Jul 2006, Yu, Hao-Cheng wrote:

> Hi Imran,
>
> Usually I output stream file like this (following your code)
>
> real myvar1(8,5),myvar2(8,5)
> open(20,file='test1.dat', access='direct',recl=8*5*4)
> open(21,file='test2.dat', access='direct',recl=8*5*4)
> ........
> write(20,rec=1) myvar1
> write(21,rec=1) myvar2
>
> In ferret script
>
> file/var=myvar1/form=stream/type=r4/grid=g8x5 test1.dat
> file/var=myvar2/form=stream/type=r4/grid=g8x5 test2.dat
> save/file=test.cdf  myvar1[d=1],myvar2[d=2]
>
> If you use -byteswapio option (PGI fortran) to compile  fortran file,  you
> have to add "swap" qualifer.
> Like
>
> file/var=myvar1/form=stream/type=r4/swap/grid=g8x5 test1.dat
>
> Hope this help you
>
> Regards, dan
>
> 2006/7/6, IMRAN NADEEM <qphoton@gmail.com>:
> > Hi ferret users,
> >
> > I wrote a stream file of two variable with these fortran commands:
> >
> >       Real*4 myvar1(8,5); Real*4 myvar2(8,5)
> >
> >
> >       open (unit=20, file="test.dat", access="direct", recl=16)
> >          ...    ...    ...    ....
> >
> >
> >                myvar1(i,j)= Real(i) + Real(j) * 10.0
> >                myvar2(i,j)=-(Real(i) + Real(j) * 10.0)
> >
> >         ...    ...    ...    ....
> >       do 120 j=1, 5
> >
> >
> >          write (20,rec=j), (myvar1(i,j),myvar2(i,j), i=1,8)
> >  120  continue
> >
> >       end
> >
> >
> > myvar1(i,j) and  myvar2(i,j) have same values but with opposite signs.I 
> > read the
> > output file with the ferret commands:
> >
> > define axis/x=1:8:1 x8
> >
> > define axis/y=1:5:1 y5
> >
> > define grid/x=x8/y=y5 g8x5
> > file/var=myvar1,myvar2/grid=g8x5/format=stream  test.dat
> > show data
> > list myvar1
> > list myvar2
> >
> > I expect to see all positive values in myvar1 and all negative in myvar2. 
> > But what I get is
> >
> >
> >
> > yes? list myvar1
> >              VARIABLE : MYVAR1
> >              FILENAME : test.dat
> >              SUBSET   : 8 by 5 points (X-Y)
> >              1      2      3      4      5      6      7      8
> >              1      2      3      4      5      6      7      8
> >
> >
> >  1   / 1:  11.00 -11.00  12.00 -12.00  13.00 -13.00  14.00 -14.00
> >  2   / 2:  15.00 -15.00  16.00 -16.00  17.00 -17.00  18.00 -18.00
> >  3   / 3:  21.00 -21.00  22.00 -22.00  23.00 -23.00  24.00 -24.00
> >  4   / 4:
> >
> > 25.00 -25.00  26.00 -26.00  27.00 -27.00  28.00 -28.00
> >  5   / 5:  31.00 -31.00  32.00 -32.00  33.00 -33.00  34.00 -34.00
> > yes? list myvar2
> >              VARIABLE : MYVAR2
> >              FILENAME : test.dat
> >
> >              SUBSET   : 8 by 5 points (X-Y)
> >
> >              1      2      3      4      5      6      7      8
> >              1      2      3      4      5      6      7      8
> >  1   / 1:  35.00 -35.00  36.00 -36.00
> >   37.00 -37.00  38.00 -38.00
> >  2   / 2:  41.00
> >  -41.00  42.00 -42.00  43.00 -43.00  44.00 -44.00
> >  3   / 3:  45.00 -45.00  46.00 -46.00  47.00 -47.00  48.00 -48.00
> >  4   / 4:  51.00 -51.00  52.00 -52.00  53.00 -53.00
> >   54.00 -54.00
> >  5   / 5:  55.00 -55.00  56.00
> >  -56.00  57.00 -57.00  58.00 -58.00
> >
> >
> > What is wrong? (test.dat is attached)
> >
> > Nadeem
> > *********************************************************************************
> >
> >
> > --
> > Imran Nadeem
> > PhD Student
> > Institute of Meteorology
> > Department of Water, Atmosphere and Environment
> > Uni. of Natural Resources and Applied Life Sciences (BOKU)
> >
> > Peter-Jordan Strasse 82
> > 1190 Vienna, Austria
> >
> > Mobile: +43 699 1194 3044
> > Tel.: +43 1 47654 5614
> > Fax: +43 1 47654 5610