/// <summary>
/// Reads the variables from the netcdf file, needed when opening a new file
/// </summary>
/// <returns></returns>
private void UpdateVariableLookup(ref IDictionary <string, NetCdfVariable> lookup)
{
lookup.Clear();
int nVars;
CheckResult(NetCdfWrapper.nc_inq_nvars(id, out nVars));
var variables = Enumerable.Range(0, nVars).Select(vi => new NetCdfVariable(vi)).ToList();
foreach (var ncVar in variables)
{
lookup.Add(GetVariableName(ncVar), ncVar);
}
}