Apply a calculator to convert u and v into speed¶
This document is part of a series teaching how to Create an image of sea surface speeds
Here we assume you alred loaded 2D ocean data
Now we want to apply a “Calculator” filter to compute the absolute speed from the velocity. Choose Filters->Common->Calculator, or use the calculator symbol just above the pipeline.
In the calculator, you can chose the data type to operate on (“cell data” is correct here), give your result variable a sensible name – we chose
vel here –
speed would have been correct…
Naming your output immediately is useful, as color maps are associated with these names, so “Result” can lead to conflicts and hassle once you have a second calculator.
In the next field, you can define the equation that is computed. We want to use:
You can also use the drop-down menus at the bottom to get access to the variables available (sorted by scalars and vector quantities).
The result should look similar to this:
With the speed computed, you can Chose a different colormap
Alternatively, you can Rescale the colormap to a custom range