private void generateInitialLineData() {
            int numValues = 7;

            List<AxisValue> axisValues = new ArrayList<AxisValue>();
            List<PointValue> values = new ArrayList<PointValue>();
            for (int i = 0; i < numValues; ++i) {
                values.add(new PointValue(i, 0));
                axisValues.add(new AxisValue(i).setLabel(days[i]));
            }

            Line line = new Line(values);
            line.setColor(ChartUtils.COLOR_GREEN).setCubic(true);

            List<Line> lines = new ArrayList<Line>();
            lines.add(line);

            lineData = new LineChartData(lines);
            lineData.setAxisXBottom(new Axis(axisValues).setHasLines(true));
            lineData.setAxisYLeft(new Axis().setHasLines(true).setMaxLabelChars(3));

            chartTop.setLineChartData(lineData);

            // For build-up animation you have to disable viewport recalculation.
            chartTop.setViewportCalculationEnabled(false);

            // And set initial max viewport and current viewport- remember to set viewports after data.
            Viewport v = new Viewport(0, 110, 6, 0);
            chartTop.setMaximumViewport(v);
            chartTop.setCurrentViewport(v);

            chartTop.setZoomType(ZoomType.HORIZONTAL);
        }
Generates initial data for line chart. At the begining all Y values are equals 0. That will change when user
will select value on column chart.
hellocharts-samples/src/lecho/lib/hellocharts/samples/LineColumnDependencyActivity.java