## Thresholds and interpolation {#thresholds-and-interpolation}

This example XML file is SE compliant. It uses interpolation to plot a reanalysis of sea surface temperature as a colour map and thresholds to plot the analysis error as degrees of blackening, also as a colour map.
[include](thresholds.xml)

The resulting output image and its legend are shown below:
![](../images/thresholds.png)

![](../images/thresholds-legend.png)

In this and all the legends that follow the topography is there to indicate regions where there is a degree of opacity. In this case it is where there is no data present for the SST over land.