Adding interval to legend of heat map

Hi Elaine,

Thanks for your question.
The HeatmapColorMap control has an Axis inside, which can be styled via the AxisStyle property:
https://www.scichart.com/documentation/v5.x/webframe.html#SciChart.Charting~SciChart.Charting.Visuals.HeatmapColorMap~AxisStyle.html

So almost everything in our documentation concerning Axes can be applied to this internal axis. For instance, here is how you can change ticks and their frequency:
https://www.scichart.com/documentation/v5.x/webframe.html#Axis%20Ticks%20-%20MajorDelta,%20MinorDelta%20and%20AutoTicks.html
https://www.scichart.com/documentation/v5.x/webframe.html#Axis%20Ticks%20-%20TickProvider%20and%20DeltaCalculator%20API.html

Default AxisStyle looks like this:

<Style TargetType="axes:AxisBase">
    <Setter Property="DrawMajorBands" Value="False" />
    <Setter Property="DrawMajorGridLines" Value="False" />
    <Setter Property="DrawMinorTicks" Value="True" />
    <Setter Property="DrawMajorTicks" Value="True" />
    <Setter Property="AutoRange" Value="Never" />
    <Setter Property="MaxAutoTicks" Value="5" />
</Style>

Please try these suggestions.