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Here is a work around for this auto range without zero problem with createXYLineChart. Create an XYPLot XYItemRenderer renderer1 = new StandardXYItemRenderer(); this.YAxis = new NumberAxis(Graph_Ylabel); XYPlot subplot = new XYPlot((XYDataset) this.data, this.XAxis, this.YAxis, renderer1); this.YAxi...

You probably have some static variables and/or functions if you copied the code from one the examples. Get rid of the static stuff.