MA2051 - Ordinary Differential Equations
Matlab - Commands specific to MA 2051 






   Commands developed especially for MA 2051 include





dfield   Direction field of
first-order equation 



weuler    Numerical approxim
ation to solution of
                initial-value problem via Euler method



wheun     Like weuler but uses Heun method 



wrk4      Like weuler but uses fourth-order
                Runge-Kutta






To learn how to use weuler, for example, type help weuler.


    Each of these commands uses a so-called M-file to describe the
differential equation in the form y' = f(t, y); e.g.
, for the
logistic equation  
tex2html_wrap_inli
ne352 ,P replaces y and  tex2html_wrap_inline358 .  The correspo
nding M-file is

% logistic.m - logistic equation
% P' = a*P - s*P^2

function Pprime = logistic(t, P)   % Note lack of ; after function line
a = 0.0282;
s = 0.00021;
Pprime = a*P - s*P.^2;

Comments are preceded by %.  Note that a and s have been
given specific values so that this M-file can return the numerical
value of the slope Pprime at any given values of t and
P.


Next:
Simple Plotting




  

    

© 1996 by Will Brother.
All rights Reserved. File last modified on November 21, 1996.