R help - Jul 2008 - Question concerning Furness iteration & subprogram/modules

Dear all,

I have basically two questions were some help would be very useful.
The first question is whether there exists a package that performs Furness
iterations.
In the field of transportation, growth factor models are estimated using
this iterative procedure.
It encompasses and iterative procedure of multiplying matrix elements by the
ration of the sum over all columns divided by a goal target,
and multiplying all matrix elements by the ratio of the sum over all rows
divided by a goal target. Does such procedure exists already in R?

The second question I have is whether it is possible to store subprograms
(modules) in a name, to reduce line of code, and make code more readable.
I use r-code to generate activity-travel patterns, and afterwards I have a
loop were I regenerate those patterns using the same code. Any idea how
I could store subprograms (not functions?).

If anyone has some answers for me I would greatly appreciate it.

Best wishes,

Mario

 

 


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