Hello I found a post (Chart cubic interpolation) that was giving tip for using renderer into chart but I got weird line with precision 15 and I try different and its not better. When I got 2 data that are the same value sometime its curving for no reason. Am putting the simple code that I use and share 2 picture. The script for now is on mouse press action
rom org.jfree.chart.renderer.xy import XYSplineRenderer
chart = event.source.chart
plot = chart.getXYPlot()
renderer = XYSplineRenderer()
# The Precision makes curve smooth ! You can play with changing the numbers.
renderer.setPrecision(15)
plot.setRenderer(renderer)
