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Metview 3 had a Vectors icon which was used for combining two scalar fields and plotting them as a vector pair. It also allowed the use of a third field for the purpose of colouring the vector arrows. This functionality is now in a new icon, Grib Vectors.
ODB
Metview 4 completely revised its handling of ODB data and does not recognise any Metview 3 ODB icons. Consequently, such icons will not be visible in Metview 4. However, all the ODB functionality of Metview 3, plus a lot more, is available in Metview 4. Please see the Tutorials page for the ODB tutorial.
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Another change in Macro is the expansion of the vector data type (see Vectors). Many Macro functions which previously returned lists of numbers will now return a vector (which is more efficient). This should mostly be transparent, since accessing a vector's elements is the same as for a list. However, user functions which explicitly test whether the returned variable is a list should be revised. See List of Operators and Functions.
Output Formats in Macro
Instead of a single output function, Metview 4 uses a set of functions to specify the desired output format, one for each type: ps_output, png_output, etc. One way to see the possible parameters for these functions is to type the appropriate function name in the Macro Editor and press F5 for an interactive help tool.
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