SimplePlotter.groovy

@ComponentInfo(name="SimplePlotter", category="ODE")
public class SimplePlotter implements Serializable {
    private static final long serialVersionUID = 1L;

    transient private BufferedImage image;

    @OutputInfo(options="fixedAspectRatio=true")
    public BufferedImage plot(
            @ParamInfo(name = "Input Trajectory") ArrayList<double[]> t1) {

        image = new BufferedImage(640, 640, BufferedImage.TYPE_INT_ARGB);

        // init paint device
        Graphics2D g2 = image.createGraphics();
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setColor(new Color(154, 158, 166));

        Composite original = g2.getComposite();
        AlphaComposite ac1 = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.65f);
        g2.setComposite(ac1);

        float strokeWidth = 4.0f;
        g2.setStroke(new BasicStroke(strokeWidth));
        g2.setComposite(original);

        // trajectory 1
        g2.setColor(Color.GREEN);

        double minX = Double.MAX_VALUE;
        double minY = Double.MAX_VALUE;

        double maxX = Double.MIN_VALUE;
        double maxY = Double.MIN_VALUE;

        // find min / max values
        for (double[] v1 : t1) {
            double xValue = v1[1];
            double yValue = v1[2];

            if (minX > xValue) {
                minX = xValue;
            }
            if (minY > yValue) {
                minY = yValue;
            }

            if (maxX < xValue) {
                maxX = xValue;
            }
            if (maxY < yValue) {
                maxY = yValue;
            }
        }

        double dx = Math.abs(maxX - minX);
        double dy = Math.abs(maxY - minY);

        double xScale = (image.getWidth() -strokeWidth*2 )/ dx;
        double yScale = (image.getHeight() -strokeWidth*2 )/ dy;

        double xOffset = (maxX + minX) / 2;
        double yOffset = (maxY + minY) / 2;

        int xImageOffset = image.getWidth() / 2 - (int) (xOffset * xScale);
        int yImageOffset = image.getHeight() / 2 - (int) (yOffset * yScale);

        int x = (int) (t1.get(0)[1] * xScale) + xImageOffset;
        int y = (int) (t1.get(0)[2] * yScale) + yImageOffset;
        int xTmp = (int) (t1.get(0)[1] * xScale) + xImageOffset;
        int yTmp = (int) (t1.get(0)[2] * yScale) + yImageOffset;

        // plot the trajectory
        for (double[] v1 : t1) {
            x = (int) (v1[1] * xScale) + xImageOffset;
            y = (int) (v1[2] * yScale) + yImageOffset;

            g2.drawLine(xTmp, yTmp, x, y);
            xTmp = x;
            yTmp = y;
        }

        g2.dispose();

        return image;
    }
}