Hi Rolf,

The chart calculates the min and max values before it is rendered. The NAxis.SeriesRange property gives access to the calculated min and max for all series that are scaled on a given axis. You can use this property either in the OnBeforePaing method of the chart paint callback (1), or after you explicitly invoke chart calculation (2):

(1)

chart.PaintCallback = paintCallback;

public class MyPaintCallback : INPaintCallback
{
     public void OnBeforePaint(NPanel panel, NPanelPaintEventArgs eventArgs)
     {
         NChart chart = nChartControl1.Charts[0];
         NAxis axisY = chart.Axis(StandardAxis.PrimaryY);
         NRange1DD range = axisY.SeriesRange;
     }

     ...
}

(2)

nChartControl1.Document.Calculate();
nChartControl1.Document.RecalcLayout(nChartControl1.View.Context);
NAxis axisY = chart.Axis(StandardAxis.PrimaryY);
NRange1DD range = axisY.SeriesRange;

 

You can also calculate the min max values manually from the series data, there is no need to execute db queries again.

I hope this helps,

Best Regards,
Milen

I have a chart with multiple surfaces and made a little data manipulation tab so i can change the look of each surface. since the data for each surface can be manipulated (data base is a access DB and the surface data is generated through queries) getting the min max values from the db is taking to long. I want to display the min/max values for the "Altitude" (primary Y axis) and manipulate the color range according to the min/ max values. The color range manipulation is already implemented, but i don´t want to run through the query again just to get min max values. Can they be determined from the existing surface data?