Axes
The X Axis and Y Axis cards control the scale and labeling of the coordinate system on which the heatmap is plotted. Both axes are always numeric (continuous).
Common Properties
Both axes share the same set of options:
| Property | Description | Default |
|---|---|---|
| Show Axis | Show or hide the axis line, tick marks, and tick labels | On |
| Show Title | Display an axis title | On |
| Title | Custom title text (leave empty to use the field name from the data role) | "" |
| Range Min | Manual lower bound for the axis scale (leave empty for auto) | Auto |
| Range Max | Manual upper bound for the axis scale (leave empty for auto) | Auto |
Auto Range
When Range Min and Range Max are left empty, each axis is scaled to the extent of the X Axis or Y Axis data role values respectively, with a small padding added so the outermost sample points are not clipped against the plot border.
If you use the heatmap across multiple report pages and want a consistent coordinate space, set explicit Range Min / Range Max values. This prevents the scale from jumping when the data changes between pages.
The axis range also affects where isolines appear: the interpolation surface is only computed within the plotted area. Sample points outside the manual range are still used to compute the interpolation but their markers and labels will be clipped.