Re: 20020618: netCDF: Problem displaying array of values

>To: "address@hidden" <address@hidden>
>cc: "Bob' 'Keeley (E-mail)" <address@hidden>
>From: Naveenta Anand <address@hidden>
>Subject: netCDF: Problem displaying array of values
>Organization: UCAR/Unidata
>Keywords: 200206181701.g5IH1K603595

Hi Naveenta,

> Kindly help if you have any experience with the follows. I am using netCDF 
> library for C. Those, who are using any other language than C can also help 
> since I see a problem with netCDF function calls (i.e.netCDF routines).
> 
> PROBLEM SCENARIO:
> 
> My variable is called station_parameter and this should display as follows:
> "TEMP"
> "PSAL"
> "PRES"
> There are three possible values as above for station_parameter
> 
> And the dimension set of this variable comprises of 3 dimensions i.e. 
> N_PROF,N_PARAM_LEN,STRING4 where:
> N_PROF = 1
> N_PARAM_LEN = 3
> STRING4 =4
> 
> The variable structure finally is 
> station_parameter(N_PROF,N_PARAM_LEN,STRING4)
> 
> -------------- Variable definition -----------------
> if (n_param_len != 0) {
>                               station_parameters_dims[0] = n_prof_dim;
>                               station_parameters_dims[1] = n_param_dim;
>                               station_parameters_dims[2] = strln4_dim;
> stat=nc_def_var(ncid,"STATION_PARAMETERS",NC_CHAR,RANK_station_parameters,
>                      station_parameters_dims,&station_parameters_id);
>                               check_err(stat,__LINE__,__FILE__);
>                       }
> where RANK_station_parameters = 3.
> 
> ------------ Adding values to variables -----------
> 
>               {
>                       size_t astart[] = {0,0,0};
>                       size_t acount[] = {1,3,4};
>                               acount[0] = n_prof_len;
>                               acount[1] = n_param_len;
>                               acount[2] = strln4_len;
>                               astart[0]=0;
>                               for (i=0;i < n_param_len;i ++)
>                                {
>               if ( i == (n_param_len -1))
>                               strcpy(stn.prof[i].prof_type,"PRES");
>               stat = nc_put_vara_text(ncid, station_parameters_id, astart, 
> acount,stn.prof[i].prof_type);
>               check_err(stat,__LINE__,__FILE__);
>                          astart[0]++;
>                               }
>                       }
> where: stn.prof[i].prof_type is -
> TEMP when i=1
> PSAL when i=2
> PRES when i=3.
> 
> With the above routines, my variable displays as follows in the netCDF file:
>  STATION_PARAMETERS =
>   "TEMP",
>   "\000N\0007",
>   "\0001" ;
> 
> WHEREAS:
> 
> As mentioned above, I am trying to output the following pattern from 
> station_parameter:
> "TEMP"
> "PSAL"
> "PRES"
> There are three possible values as above for station_parameter.
> 
> ----------------------------------------------------------------------------  


The array acount[] should specify the "shape" of the slab of values
you are writing, that is the number of indices along each dimension.
Since you are writing only 4 characters along the last (strln4)
dimension, this shape is 1 by 1 by 4, so you want acount initialized
as {1, 1, 4} and not changed after that:

                        size_t acount[] = {1,1,4};

The array astart[] should specify where each write starts in the 1 by
3 by 4 cube of characters.  The first write will start at the {0,0,0}
position but the next write will start at {0,1,0} and the last write
at {0,2,0}.  So you can use your i index for astart[1], or you can
increment astart[1] each time through the loop.

So here is one version to do what you want:

 {
         size_t astart[] = {0,0,0};
         size_t acount[] = {1,1,4};
         for (i=0;i < n_param_len;i ++)
                  {
                  stat = nc_put_vara_text(ncid, station_parameters_id, astart, 
                                          acount, stn.prof[i].prof_type);
                  check_err(stat,__LINE__,__FILE__);
                  astart[1]++;
                  }
 }

Another way to do it would be:

 {
         size_t astart[] = {0,0,0};
         size_t acount[] = {1,1,4};
         for (i=0;i < n_param_len;i ++)
                  {
                  astart[1] = i;
                  stat = nc_put_vara_text(ncid, station_parameters_id, astart, 
                                          acount, stn.prof[i].prof_type);
                  check_err(stat,__LINE__,__FILE__);
                  }
 }

I haven't checked these by compiling and running them, because I
didn't have the context for the fragment of code, but I think either
of the above should work.  If not, please write back ...

--Russ

_____________________________________________________________________

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