Axis range

Hi Alex

Clamping Axis.Visiblerange in SciChart WPF can be achieved with a VisibleRangeChanged event handler

Take a look at Clipping the Axis.VisibleRange on Zoom and Pan

Clipping Axis.VisibleRange in Code To clip the VisibleRange and force a certain maximum or minimum, just use the following code:

axis.VisibleRangeChanged += (s, e) =>
  {
     // e is VisibleRangeChangedEventArgs
     // Assuming axis is NumericAxis
  
     if (e.NewVisibleRange != null && e.NewVisibleRange.Min < 0)
     {
        // Force minimum visiblerange to zero always
        ((NumericAxis)sender).VisibleRange = new DoubleRange(0, e.NewVisibleRange.Max);
     }
  };
  

There are other methods in there such as using VisibleRangeLimit but these have their limitations (no pun intended), such as not clamping when user zoom/pan occurs

Hi Andrew,

Thank you for your answer!

In our case, we do not want to clip the visible range. What I am trying to achieve is the following: I have a series with some number of data points. Let us assume that in this series the lowest value is 67 and the highest value is 71. If we plot this normally with autorange = once, it will auto-range the Y axis to the visible range (67, 71). What I would like is to use the autorange feature so it automatically calculates the maximum range of Y axis but I would like to minimum range for Y axis to be 0 not 67 when we use ZoomExtentsModifier. The rest of the behaviors I do not want to affect: zooming, panning, dragging. What I am trying to say is that when I play with the zoom I do not want to restrict it. For example, if I play with the zoom I would like the range to modify to let’s say (68, 70) but also (-20, 100) (no clipping). But when we double-click the chart to trigger the ZoomExtentsModifier I would like to visible range to go to (0, 71) instead of (67, 71).

I am in an MVVM environment.
As I said in my comment I got it working the way I want by taking advantage of the GrowBy property. What I did was:

DoubleRange dr = axis.GetMaximumRange().AsDoubleRange();
axis.GrowBy = new DoubleRange(dr.Min / dr.Diff, dr.Max * 0.1 / dr.Diff);

This ensures that we have a 0 value as the min value of the visible range and we have a padding of 10% on the maximum side when we trigger the ZoomExtentsModifier. When I did this, I was not in an MVVM environment and I was using the NumericAxis type.

Since then, I moved to an MVVM environment and I am now using the NumericAxisViewModel type instead. But now, with this type do not have access to the GetMaximumRange() function. I need this function because in my example above it would return the visible range computed by the auto range which would be (67, 71).

Is this something we could achieve?