Visualising a recipe graphically

In this tutorial we will investigate what is going on inside of a recipe, and visualise the operators inside.

As in the previous tutorial use the cset cookbook command to find the “Mean Air Temperature Spatial Plot” recipe.

We will now visualise the steps inside the recipe using the cset graph command.

cset graph -r recipes/mean-air-temp-spatial-plot.yaml

This should open an image of a visualisation of the recipe. Each node is a step, or an operator, which does a single processing task. You can see that later operators depend on previous ones, and this relationship can be as complicated as needed.

To see more detail about each individual operator running we can use the --details flag. This shows the configuration of each operator in the recipe.

cset graph --details -r recipes/mean-air-temp-spatial-plot.yaml

Now we can see the structure of the recipe graphically, we can delve into what each operator is doing. The ellipses represent the operators, and the arrows between them show where they pass their output to the next operators.

The first operator in the recipe is read.read_cubes, however it takes a constraint on a STASH code, which is itself created by another operator, constraints.generate_stash_constraint.

This operators-running-operators behaviour is further used in the next step, where the read CubeList is filtered down to a single air temperature cube. There are two constraints used here, the STASH code, and the cell methods. These are combined into a single constraint by the constraints.combine_constraints operator before being used by the filters.filter_cubes operator.

Afterwards the cube has its time dimension removed by the mean method applied by the collapse.collapse operator, so it becomes two-dimensional. Then it passes to the plot.spatial_contour_plot and write.write_cube_to_nc operators to be plotted and saved.

You now know how to visualise a recipe, and a little about the operators it is made up of. In the next tutorial you will learn to make your own.