[netCDF #MLP-485355]: How to read a NetCDF data set with Fortran 77...

Hi Miguel,

If you look at the Fortran-77 netCDF documentation:

 http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-f77.html

you can find a description of the arguments for the nf_get_vara_real function 
in the "Variables" chapter:

INTEGER FUNCTION NF_GET_VARA_REAL(INTEGER NCID, INTEGER VARID,
                                  INTEGER START(*), INTEGER COUNT(*),
                                  REAL rvals(*))

It says that the START vector tells what index of the variable in the file is 
where to start accessing data.  The COUNT vector tells how far along each axis 
of the variable to access data.  So START and COUNT together define a sub-array 
(or "slice") of the whole variable on disk.  In particular, both START and 
COUNT must have as many vlaues as the variable's rank, in this case 4.  You 
haven't provided any value for start(4), so it's probably zero, since it has 
not been initialized.  Therefor, you are asking to start access at the (1, 1, 
1, 0) element of the variable, hence the error message.  If you set start(4)=1, 
your program may get farther.

If you really want to read all the values of the variable vosaline with one 
read, you could use the simpler call

  retval = nf_get_var_real(ncid, sal_varid, sal_in)

using the documented

 INTEGER FUNCTION NF_GET_VAR_REAL(INTEGER NCID, INTEGER VARID,
                                  REAL rvals(*))

which has no START or COUNT arguments, but just gets all the values.  The only 
reason to use the START and COUNT arguments in the more complicated 
nf_get_vara_real() function is if you need to read in only part of the array on 
disk, perhaps because it won't all fit into memory, or because you only want to 
process one slice at a time.

--Russ
 
  
http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-f77.html#NF_005fGET_005fVARA_005f-type
Russ Rew                                         UCAR Unidata Program
address@hidden                     http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: MLP-485355
Department: Support netCDF
Priority: Normal
Status: Closed