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Vector literals can be written using the | character :

v = |3,6,7,9,10|

Vector data types

By default, the elements of a vector are 64-bit double precision floating point values. By calling the function vector_set_default_type(type), where type can be one of 'float32' and 'float64', you can force all subsequently created vectors to contain elements of that type. A vector of float32 elements consumes half the memory of a float64 vector, but at the expense of some accuracy. The type of a vector can be queried with the dtype() function.

How operators and functions work on vectors

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If a vector is holding data representing a rectangular structure, this form could be used to extract a 'sub-area'.

A vector can also be used to provide a set of indexes to another vector:

# copies values 20, 10, 30 into r
v = |10, 20, 30, 40|
i = |2, 1, 3|
r = v[i] 

Additionally, it is possible to assign a vector to an indexed position in another vector, for example: v[4] = |99,99,99| . In this example, elements 4, 5 and 6 of v will be replaced.

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afs   = read('a.grib')        # afs is a fieldset
bfs   = read('b.grib')        # bfs is a fieldset
a     = values(afs)           # a is a vector or a list of vectors
b     = values(bfs)           # b is a vector or a list of vectors
spd   = sqrt(a*a + b*b)       # spd is a vector or a list of vectors
spdfs = set_values(aafs, spd)  # write the result back into a fieldset

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• no temporary files are generated
• computations are performed with the default of 64-bit double-precision floating point numbers
• the vector variables are held in memory
• the values() function on a fieldset with many fields will yield a list of many vectors, which may require much memory
• if this is the end of the computation, the vector variables should be freed, e.g.

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    Code Block
    language py
    a = 0 b = 0 spd = 0

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