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Subject: RE: changing variables over time
Hello Jakin
That's very easy. There are 2 ways of doing this.
Then you change the monthly values by
2. You can use real data and read the monthly rainfall from a file.
Let me know if you need help with the equations.
Best wishes,
Louise Erasmus
-----Original Message-----
I am having trouble changing variables in Cormas over a time period, for
example using different monthly averages to simulate rainfall within the
Jakin Ravalico
From: Erasmus L
Date: Sun Sep 21 2003 - 14:24:12 CEST
Firstly you need to add an attribute to the environment called rainfall
or something. Set your time step to one month.
1. Use an equation to simulate rainfall. Since rainfall is usually
periodic of nature you can use a periodic equation (using sine, cosine
or pi) that describes the real rainfall pattern to calculate the monthly
rainfall values. Your equation must have a period of 12 months and your
x-value will be one month. Y value is of course the rainfall for that
month. You can also add a random variability to it.
Residential address:
Biocomplexity Research Group
Department of Zoology
University of Stellenbosch
Stellenbosch
7602
South Africa
Tel. + 27 - 21 - 808 2604
Affiliation address:
Conservation Planning Unit
Department of Zoology and Entomology
University of Pretoria
Pretoria
0002
South Africa
Tel. +27 - 12 - 420 4048
e-mail: lerasmus@zoology.up.ac.za
Please use the residential address
From: Jakin Ravalico [mailto:jakin.ravalico@adelaide.edu.au]
Sent: 21 September 2003 11:21 AM
To: cormas@cirad.fr
Subject: changing variables over time
model.
Could anyone help with how to do this?