defineGlobalAttribute: Define a global time-varying attribute
Description
This function allows to define a global attribute of the nodeset
(i.e a variable that is identical for each node but changes over time).
Usage
defineGlobalAttribute(global)
Value
an object of class global.goldfish
Arguments
global
a data frame containing all the values this global attribute
takes along time.
Details
For instance, seasonal climate changes could be defined as a
changing global attribute.
Then, this global attribute can be linked to the nodeset by using
linkEvents()