Error in netcdf.putVar due to START argument.

I'm running a model with a daily time-step and I want to archive monthly averages of each variable of interest. So, I'm trying to write average monthly results into netCDF variables using netcdf.putVar

Here's a piece of my code to help you understand:

    % logical array, true if time step corresponds to the end of an archiving time step (=end of the month)
    if Arch.islast(it) 

    % Determining the size of each variable of interest. avg is a nvar x 1 cell array. Each cell contains the monthly 
    % averages of the variable considered.
    isd = cellfun(@(x) isequal(size(Grd.z), size(x)), avg); % in the case of a 3 x 2 array
    isde = cellfun(@(x) isequal([1 size(Grd.x,2)], size(x)), avg); %in the case of a 1 x 2 array
    iss = cellfun(@(x) isscalar(x), avg); % in the case of a scalar

    % Vectors specifying the index where to write the section of values. Arch.bin = 1 x nt array, index of archiving 
    % time step to which each model time step corresponds
    start = cell(size(avg));
    [start{isd}] = deal([0 0 Arch.bin(it)-1]);
    [start{isde}] = deal([Arch.bin(it)-1 0]);
    [start{iss}] = deal([Arch.bin(it)-1]);

    %Vectors specifying the extent to which the section of values is written.
    count = cell(size(avg));
    [count{isd}] = deal([Grd.nz Grd.nx 1]);
    [count{isde}] = deal([1 Grd.nx]);
    [count{iss}] = deal([1]);

    for iv = 1:length(avg)
        netcdf.putVar(ncid, vid(iv), start{iv}, count{iv}, avg{iv});
    end

    % Zero out avg arrays
    avg = cellfun(@(x) zeros(size(x)), avg, 'uni', 0);

    end

Here's the error I get for one of the variables (i.e. Ql):

    Error using netcdflib
    The length of the START argument for Ql must be 0 instead of 2.

    Error in netcdf.putVar (line 84)
    netcdflib(funcstr,ncid,varid,varargin{:});

    Error in WCVIE2E_archivemldata (line 87)
    netcdf.putVar(ncid, vid(iv), start{iv}, count{iv}, avg{iv});

In total there are 12 variables of interest in avg. This error doesn't pop up for most variables, only for 2 of them. One of them, Ql, is a 1 x 2 array. I have already verified whether previous functions in my model did produce a 1x2 array for this variable and it seems to be the case. This error message doesn't pop up for other variables that have the same size, which I don't understand...

If anyone of you is willing to look more closely into my model, here's my GitHub: https://github.com/virginie01/WCVI-E2E. Just need to download all folders&files. To run the entire model, one needs to run the mixedlayer_examples.m code and change the "addpaths" accordingly.

I hope some of you are able to enlighten me on this ! Cheers, Virginie

Answer 1

[KSSV]

YOu need not to use such a complex functions.......reading netCDF in MATLAB is very easy. Just you want to know two functions.

ncdisp, ncread

Read about those two functions. It should make everything easy.

[Virginie Bornarel]

Hi KSSV,

Thank you for taking the time to answer my question. I don't want to read netcdf variables, I want to write data to netcdf variables. The error arises when I use the function netcdf.putVar

[KSSV]

Okay..writitng too is very easy in MATLAB. YOu need to know just two funcitons..... nccreate and ncwrite. Try out with these.....if any error. LEt me know..I shall help you.

[Virginie Bornarel]

Thank you ! So I replaced the function netcdf.putVar with ncwrite and everything works just fine now ;)