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Re: How to implement a summation function for numerical solving?
From: 
John W. Eaton 
Subject: 
Re: How to implement a summation function for numerical solving? 
Date: 
Tue, 14 Jun 2011 09:16:21 0400 
On 14Jun2011, andrewcd wrote:
 One more question:

 You have probably noticed that my code defines variables twice  once
 inside and once outside of the function. This is a pain, obviously. But
 variables defined outside of the function don't show up inside the function,
 and vice versa. There must be a way around this. Any hints? Thanks.
Pass more than one input as needed. For example,
mu = 2
xmin = 5
xmax = 10
x = xmin:.2:xmax
lx = length(x)
stp = .2
function result = eqns (z, mu, xmin, xmax, x, lx, stp)
...
endfunction
Then you can set up the call to your function with
mu = 2
xmin = 5
xmax = 10
x = xmin:.2:xmax
lx = length(x)
stp = .2
z = something;
result = eqns (z, mu, xmin, xmax, x, lx, stp)
If you need to pass this function to fsolve, which expects a function
of a single variable, then you can use an anonymous function:
mu = 2
xmin = 5
xmax = 10
x = xmin:.2:xmax
lx = length(x)
stp = .2
result = fsolve (@(z) eqns (z, mu, xmin, xmax, lx, stp), guess)
All variables not listed in the argument list of the anonymous
function are picked up from the surrounding context. So in
@(z) eqns (z, mu, xmin, xmax, lx, stp)
everything but Z is set from the variables that are in scope at the
point where the anonymous function is created.
Does that help?
jwe
 How to implement a summation function for numerical solving?, andrewcd, 2011/06/13
 Re: How to implement a summation function for numerical solving?, Liam Groener, 2011/06/13
 Re: How to implement a summation function for numerical solving?, andrewcd, 2011/06/13
 Re: How to implement a summation function for numerical solving?, andrewcd, 2011/06/14
 Re: How to implement a summation function for numerical solving?, Kimmo Luoma, 2011/06/14
 Re: How to implement a summation function for numerical solving?,
John W. Eaton <=
 Re: How to implement a summation function for numerical solving?, andrewcd, 2011/06/15
 Re: How to implement a summation function for numerical solving?, Liam Groener, 2011/06/16
 Re: How to implement a summation function for numerical solving?, Liam Groener, 2011/06/16
 Re: How to implement a summation function for numerical solving?, andrewcd, 2011/06/16