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Dial (gauge) via image object

HOW-TO APPLICATION DEVELOPER STAND: JUL 2026 GILT FUER NUCLOS 4.2026.X

A dial (gauge) cannot be shown as a standard chart but via an image object whose picture is drawn by a JFreeChart DialPlot (based on DialDemo2.java).

Summing the value correctly

To output a sum over a variable:

• Create a variable with Reset Type = Report (sum over all records).
• Set Evaluation Time = Report on the image – the value is passed to image generation only after the full calculation.

Implementation

A scriptlet/customizer class turns the value into a java.awt.Image: it builds a DialPlot with scale, needle and cap, wraps it in a JFreeChart and draws it via Graphics2D into a BufferedImage (e.g. 250×250 px):

Graphics2D g2 = image.createGraphics();
jfreechart.draw(g2, new Rectangle2D.Double(0.0, 0.0, 250, 250));
g2.dispose();
return image;

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