...
When you right-click on an icon, a context-sensitive menu appears.
Choose examine to quickly see the structure of the GRIB file.
...
The Magnifier button in the toolbar toggles the magnifier tool on and off. Unlike Zoom, this is a purely graphical enlargement of the plot. It is usedmainly used mainly to inspect small text such as contour labels. The magnifying glass can be moved and resized using the mouse, and the magnification scale on its left-hand side can also be adjusted.
...
Visualise the data again, and drag your new Coastlines icon into the Display Window.
Your Coastlines icon can be dragged into any plot, and later we’ll see how to store useful icons so that they can be easily accessed from anywhere.
...
Metview's default map projection is Cylindrical. However, meteorologists often use other projections when plotting data.
Create a new Geographic Geographical View icon and rename it to polar_europe. Edit the icon and change the following parameter:
...
Save the changes and visualise the icon. Drop the GRIB data icon into the Display Window to see it on the new map. It is also possible to visualise the GRIB icon and then drop the Geographic Geographical View icon into the plot to achieve the same effect. Have a look at some of the other projections on offer, then go back to polar stereographic.
...
Use the Zoom tools to enlarge the European area and use the Area tool to select a region over Europe. Click Ok to save your selection - your choices will now be updated in the Geographic Geographical View editor. Click Apply in the Geographical View editor to save everything. Plot your data in this view to confirm that the area and projection are as desired.
Linking the Coastlines icon with the
...
Geographical View Icon
Although they can be used separately, the Coastlines icon can be linked into the Geographic Geographical View icon through the concept of embedded icons.
...
Metview incorporates a powerful Macro language, which can be used for tasks ranging from simple automation of tasks to complex post-processing of data. We will now create a simple macro which reads the GRIB file and plots it in our chosen projection.
Create a new Macro icon and edit it. This time we see a code editor, custom-built for the Macro language. The editor can automatically translate Metview icons into Macro code, so do the following:
...
We will now change these isolines to black. Create a new Contouring icon and rename it to black_contour. Edit it and set the following:
...
Drop this into the Display Window - the result is not as intended! The new Contouring definition was applied to both fields, not just the geopotential. Close the Display Window and re-run the macro to get us back to the point before we added the geopotential. This time, select both the z500.grb and black_contour icons and drop them together into the Display Window. This forces the association between the data and the visual definition. You might want to remove the temperature isolines by setting Contour to Off in the macro.
...
Spend some time exploring the Contouring icon. Here are some suggestions:
...
Spend some time exploring the Coastlines icon. Here are some suggestions:
...
| Section | ||||
|---|---|---|---|---|
|
...