         lineplot = false
 
         id = definition.id
-        @ordinal = @ordinal + 1
+        @ordinal++
 
         if !definition.lineplot
             index = @options.datasetIndex++

    removeDataset: (id) ->
        return false unless @datasets[id]?

        i = @datasets[id].index
        lp = @datasets[id].lineplot
        ordinal = @datasets[id].ordinal
        delete @datasets[id]

        if lp


        # object to hold individual data points / data ranges
        @datasets = {}
        @ordinal = 0

        @timetickDate = false
        @simplifyDate = d3.time.format("%d.%m.%Y - %H:%M:%S")
