[netCDF #ZHC-323580]: creating x,y,z 3d volumes

Hi Louis,

> Description of problem: I would like to build up a 3D volume one layer at a 
> time.   Can I do it as follows?
> Using the C library.
> 
> start[0] = 0;  //time = unlimited
> start[1] = 0;  // nlev
> start[2] = 0;  // lat
> start[3] = 0;  // lon
> 
> end[0] = 1;
> end[1] = 0;
> end[2] = num_lat;
> end[3] = num_lon;
> 
> lvl = 0;
> do
> {
> {read data}
> start[1] = lvl;
> end[1] = lvl;
> if ((erret = nc_put_vara_float(ncid, var_id, out_start, out_end, out_data)))
> errprt(prog, erret, "Cannot write data");
> lvl = lvl +1;
> }while ( lvl < num_lev);

No, because the argument you have called "out_end" is documented as 

    count

    A vector of size_t integers specifying the edge lengths along each
    dimension of the block of data values to be written. To write a
    single value, for example, specify count as (1, 1, ... , 1). The
    length of count is the number of dimensions of the specified
    variable. The elements of count correspond to the variable's
    dimensions. Hence, if the variable is a record variable, the first
    element of count corresponds to a count of the number of records to
    write.

    Note: setting any element of the count array to zero causes the
    function to exit without error, and without doing anything.

So you want to set

  end[1] = 1;

and leave it unchanged from that value in your loop to write just
one level (and just one time) for each iteration of the loop.  You may
also want to change the name of the variable from "end" to "count" or
something similar, to make the code easier to maintain.

Otherwise your code looks OK.

--Russ


Russ Rew                                         UCAR Unidata Program
address@hidden                     http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: ZHC-323580
Department: Support netCDF
Priority: Normal
Status: Closed