How to organize data in matrix

Hi, I have a dataset that is in netCDF format. These data are precipitation and have 5 variables. I reduced the 2D I need (lat, lon) and now I need to save to a 3D cell with fixed lat and lon and time varying. I am unable to save so that they are not subscribed to previous data. Any help will be appreciated.

[meghannmarie]

I am not really understanding, are you trying to clip the data down to a specific or range of lat/lon/time? If so, what are the dimensions on the 5 variables?

[meghannmarie]

Upload a sample netcdf file if you can or link to one.

Or do a ncdisp(file) and post the output.

[John D'Errico]

Sorry, but this is gibberish so far as you have written. You may understand what you are asking to do, but it makes no sense at all.

So give a SMALL, SIMPLE example, only a few numbers. Then show what you would hope to find as a result.

There is no need to even post a netcdf file, as that just means you have not read it into MATLAB yet. It is just a bunch of numbers.

If you want help, then make it easy for somone to help you.

[Stephen23]

FELIPE PIMENTEL's "Answer" moved here:

Sorry it was not clear.

I have files in netCDF format with the following variables:

netcdf4_classic
Dimensions:
           S = 1
           M = 10
           Y = 181
           X = 360
           L = 7
Variables:
    S 
           Size:       1x1
           Dimensions: S
           Datatype:   double
           Attributes:
                       units    = 'months since 1982-01-01'
                       calendar = 'standard'
                       axis     = 'N'
    M 
           Size:       10x1
           Dimensions: M
           Datatype:   single
           Attributes:
                       units     = 'Unitless'
                       long_name = 'Ensemble Member'
                       axis      = 'M'
    Y 
           Size:       181x1
           Dimensions: Y
           Datatype:   single
           Attributes:
                       units     = 'degrees_north'
                       long_name = 'latitude'
                       axis      = 'Y'
    X 
           Size:       360x1
           Dimensions: X
           Datatype:   single
           Attributes:
                       units     = 'degrees_east'
                       long_name = 'longitude'
                       axis      = 'X'
    L 
           Size:       7x1
           Dimensions: L
           Datatype:   single
           Attributes:
                       units         = 'months'
                       long_name     = 'Lead'
                       standard_name = 'forecast_period'
                       axis          = 'L'
    pr
           Size:       360x181x7x10x1
           Dimensions: X,Y,L,M,S
           Datatype:   double
           Attributes:
                       units         = 'mm'
                       long_name     = 'Precipitation'
                       missing_value = -999
                       fill_value    = -999

For "M", I have a mean and for "L" I select 1, 2 or 3 as needed. I need to open these files one by one, select lat and lon for South America and write in a continuous matrix with monthly data from 1982/jan to 2010/dec.

That is, I need an organized 3D matrix like lat, lon and monthly interval precipitation. That way my matrix would be 60x45x348 (lat x lon x time) All the part of selecting and extracting the data I am doing. The problem is saving these files to a new array because I'm overwriting over the previously read data and the array ends up as 2D with the last read data.

Answer 1

[meghannmarie]

Did you preallocate output array?

output_array = nan(60,45,348);
for time_idx = 1:348
    output_array(:,:,time_idx) = ncread(file,'pr',start,count);   
end

[FELIPE PIMENTEL]

Thank you very much.

That was exactly what I was looking for.

Thanks