def update_dataset(self,dataStr,flatten=False):
        '''
        update class with a data structure.
        
        :keyword flatten: use this to automatically flatten variables (squeeze dimensions)
        '''

        #Load keys and dimensions
        #########################
        dataDim = dataStr.pop('_dimensions',{})
        attrStr = dataStr.pop('_attributes',{})
        ndims = dataDim.pop('_ndims',0)
        dimensions = [dataDim.keys(),dataDim.values()]
        
        keys = dataStr.keys()
        if len(keys) == 0:
            self.warning(2, 'No data loaded')
            return
        self.message(2, 'Loaded variables : '+str(keys))
        
        #Check what is the current variable type
        isStructure = True if isinstance(dataStr[keys[0]],dict) else False
        
#        datalen = [np.size(dataStr[key]) for key in keys]
        datalen = [list(np.shape(dataStr[key]['data'])[::-1]) for key in keys] if isStructure else [list(np.shape(dataStr[key])[::-1]) for key in keys] #Shape is inverted wrt to order of dimensions to be consistent with check_variable
        if isStructure :
            varDim = [list(dataStr[key]['_dimensions'])[1:] for key in keys]
            ind = [where_list(vDim,dimensions[0]) for vDim in varDim] #Dimensions indices from actual variables' dimensions
            
            #Check dimension lengths
#             dimOk = np.array([enum[1][0] == dimensions[1][ind[enum[0]][0]] for enum in enumerate(datalen)])
            dimOk = [any([enum[1][ii] == dimensions[1][jj] for ii,jj in enumerate(ind[enum[0]])]) for enum in enumerate(datalen)]
            

            if any([not d for d in dimOk]) : 
                notOk = np.where(~np.array(dimOk))[0]
                print datalen
                
                self.Error('Problem with {0} variables : {1}'.format(len(notOk),','.join(np.array(dataStr.keys())[notOk])))
        else :
            ind = [where_list(dlen,dimensions[1]) for dlen in datalen] #Dimensions indices from variable length
            if (np.array(ind).sum() == -1)!= 0 : self.Error('At least one variable have not been properly defined')
            
        dimname = [np.array(dimensions[0])[i].tolist() for i in ind]  #Get correspondance between data structure dimensions and variables
                
        curDim, nself=self.get_currentDim()
        createDim=np.array([np.array([w == -1 for w in where_list(j, curDim[0])]) for i,j in enumerate(dimname) ])
        createDim=np.squeeze(createDim)
#        curInd = atools.where_list(dimname_reduced,curDim[0]) #Get correspondance between data structure dimensions and object dimensions
        
#        createDim = (np.array(curInd) == -1) #Get dimensions to be created   
        toCreate = np.array([not self.__dict__.has_key(key) for key in keys])
        
        updateDim=[]  
        
        self.message(2, 'Updating object with '+str(['{0}({1}:{2})'.format(i[0],i[1],i[2]) for i in zip(*(keys,dimname,datalen))]))
        
        #Update variables available in files
        for enum in enumerate(keys) :
            
            ind=enum[0]
            key=enum[1]
            
            #Load variable
            ##############
#            var=dataStr.get(key)
            dum=dataStr.get(key).pop('data') if isStructure else copy.deepcopy(dataStr.get(key)) 
            if flatten :
                if isinstance(dum,dict) :dum['data']=dum['data'].flatten()
                else : dum=dum.flatten()
            
            if not isStructure :
                dum={'_dimensions':dum._dimensions if hasattr(dum,'_dimensions') else {},
                      '_attributes':dum._attributes if hasattr(dum,'_attributes') else {},
                      'data':dum}
            else :
                dumStr=dataStr.get(key)
                dumStr.update({'data':dum})
                dum=dumStr

            dumDim=dimStr(dimname[ind],datalen[ind])

#             if dataStr[key].has_key('_attributes'):
#                 dum.update(dataStr[key]['_attributes'])
#            if isinstance(dum,np.ma.masked_array) : 
            
#            #Get associated dimensions
#            ##################################
#            datalen = datalen[ind]#[len(dataStr[key]) for key in keys]
#            ind = atools.where_list([datalen],dimensions[1])[0]
#            if (ind == -1) : self.Error('Dimensions of current variable ('+key+') have not been properly defined')
#            dimname = dimensions[
            
            #Initialize variable if required
#            if toCreate :
#            updateDim.append(self.create_Variable(key, dum, dimensions={dimname[ind]:datalen[ind]},toCreate=toCreate[ind],createDim=createDim[ind]))
            updateDim.append(self.create_Variable(key, dum, dimensions=dumDim,toCreate=toCreate[ind],createDim=createDim[ind]))

        
        #Extend missing variables
#         missing__keys = list(set(self.par_list).difference(keys))
#         for enum in enumerate(missing__keys) :
#             ind=enum[0]
#             key=enum[1]
#             updateDim.append(self.create_Variable(key, np.ma.repeat(self.dist_to_coast_leuliette.fill_value), dimensions=dumDim,toCreate=False,createDim=False))
        
        
        #Final sequence
        
        zipped_upd=zip(*(np.hstack(dimname)[~np.hstack(createDim)],np.hstack(datalen)[~np.hstack(createDim)]))
        updateDim_List = np.array(list(set(tuple(i) for i in np.array(zipped_upd,dtype='|S16').tolist()))) #2D unique
#        updateDim_List = np.unique(np.array(zipped_upd,dtype='|S16')) #[str(i) for i in datalen]
#        if updateDim_List.size > 0 : updateDim_List.resize((2,updateDim_List.size/2))
#        updateDim_List = np.unique(zip(*(np.array(dimname)[~createDim],np.array(datalen)[~createDim]))) #[str(i) for i in datalen]

        zipped_dims=zip(*(np.hstack(dimname)[np.hstack(createDim)],np.hstack(datalen)[np.hstack(createDim)]))
        createDim_list = np.array(list(set(tuple(i) for i in np.array(zipped_dims,dtype='|S16').tolist()))) #2D unique
#        clist, inv = np.unique(np.array(zipped_dims,dtype='|S16'),return_inverse=True) #RQ : THIS WILL FAIL IF NUMBERS HAVE MORE THAN 16 DIGITS #[str(i) for i in datalen]
#        if createDim_list.size > 0 : createDim_list.resize((2,createDim_list.size/2))
        
#        createDim_list = np.unique(zip(*(np.array(dimname)[createDim],np.array(datalen)[createDim]))) #[str(i) for i in datalen]
        
        for dname,dim in createDim_list :
            self.create_Dim(dname, np.int(dim))
        
        for dname,dim in updateDim_List:
            self.update_Dim(dname, np.int(dim))
update class with a data structure.
        
        :keyword flatten: use this to automatically flatten variables (squeeze dimensions)