==  Function: ==

As for [https://www.meteo.unican.es/trac/meteo/wiki/SpecsEuporias/Interfaces/RPackage/Python Phyton], a ''Matlab'' function ([https://www.meteo.unican.es/trac/MLToolbox/browser/MLToolbox/trunk/MLToolbox_experiments/antonio/system4/matlab/loadSystem4.m loadSystem4.m]) has been created in order to access the ''SPECS-EUPORIAS Data Portal'' in a user-friendly way. 
The ''loadSystem4'' function is called this way:

{{{
 [data,run,ens,frc,lat,lon] = loadSystem4(dataset,var,season,leadMonth,'members',members,'xlim',xlim,'ylim',ylim,'user',user,'password',password);
}}}

The input arguments are next described:

* `dataset`: A character string indicating the full URL path to the OPeNDAP dataset. Currently, the accepted values correspond to the System4 datasets described in Section [https://www.meteo.unican.es/trac/meteo/wiki/SpecsEuporias/DataServer/Datasets Available Datasets].
* `var`: Variable code. Argument values currently accepted are `tas`, `tasmin`, `tasmax`, `pr` or `mslp`, as internally defined in the vocabulary for System4 following the nomenclature displayed in the table below. However, note that new variables and datasets will be progressively included. 
* `season`: A cell of two strings indicating the first and final months of analysis. A single month can be specified (as in the above example) or a standard season (e.g. `season = [12,1,2]` for standard Boreal winter, DJF).
* `leadMonth`: Lead time (in months) to consider. For instance, `leadMonth = 1` for January forecasts means considering the initialization of the first of December.
* `members`: Vector with the list of members to select. 
* `xlim`: Vector of length = 2, with minimum and maximum longitude coordinates, in decimal degrees, of the bounding box selected.
* `ylim`: Vector of length = 2, with minimum and maximum latitude coordinates, in decimal degrees, of the bounding box selected.
* `user`: Username for accessing the OPeNPAD dataset.
* `passwork`: Password for accessing the OPeNPAD dataset.

These are the arguments returned by the function:

* `data`: Cell with ''n'' elements (one for each year), in which each element (a 2-D matrix) is the data for a particular year. A 2-D matrix of ''i'' rows and ''j'' columns, ''i'' represents the forecast times and ''j'' the grid-points selected.
* `run`: Cell with ''n'' elements (one for each year) corresponding to the initialization times selected. Note that there is an initialization time associated to each forecast time.
* `ens`: List of length ''n'', where ''n'' is the number of members of the ensemble selected by the `members` argument. 
* `frc`: Cell with ''n'' elements (one for each year) corresponding to the forecasts times.
* `lat`: Vector with the latitudes of the selected domain.
* `lon`: Vector with the longitudes of the selected domain.


==  Example: ==

In this example, the '''loadSystem4''' function is used to read the maximum temperature for the Iberian Peninsula in August for the whole hindcast period (1981-2010), considering the initialization of the first of June (two-month lead time thus) for a single member (member5, for instance). 

{{{
dataset = 'http://www.meteo.unican.es/tds5/dodsC/system4/System4_Seasonal_15Members.ncml';
var = 'Maximum_temperature_at_2_metres_since_last_24_hours_surface';
 [data,run,ens,frc,lat,lon] = loadSystem4(dataset,var,{'Aug';'Aug'},2,'members',5,'xlim',[-10 5],'ylim',[35 45]);
}}}

The data can be plotted by using the functions from [https://www.mdm.unican.es/trac/MLToolbox MeteoLab], the open-source ''Matlab'' toolbox for statistical analysis and data mining in Meteorology created by the [http://www.meteo.unican.es/en/main Santander Meteorology Group].

{{{

}}}

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