Surface Plots are used to identify trends and outliers within numeric surfaces.
The Surface is made up of a series of points where each point has:
Color (represents the Z-axis)
The Surface Plot can support data sets where the X and Y positions can both be regular and irregular in their distribution.
Additionally, the color scale can be continuous or stepped to show a surface gradient.
Figure 1. A surface plot with stepped colors
Figure 2. A surface plot with continuous colors