# Shooting Method: issues with zero

2 views (last 30 days)
Laura Bell on 13 Jan 2020
Answered: Jyotsna Talluri on 17 Jan 2020
I am struggling with Problem 24.16 (see attatched). This is the code I have been using, but I keep getting the following error:
Error using fzero (line 306)
FZERO cannot continue because user-suppliedfunction_handle ==> hw7_24p16res failed with theerror below.
Undefined function 'hw7_24p16dydxn' for input arguments of type 'double'.
Error in hw7_24p16 (line 55)
[x,y]=ode45(@hw7_24p16dydxn,tspan,[5 fzero(@hw7_24p16res,L)]);
Here is my code:
clear all
close all
E=200*10^9;%in Pa
I=30000*10^(-8);%m^4
w=15*10^3;%N/m
L=3;%m
x=[0 L];
y=[0 0];
fprintf('(b) the shooting method\n')
fprintf('\n')
tspan=x;
[x,y]=ode45(@hw7_24p16dydxn,tspan,[5 fzero(@hw7_24p16res,L)]);
plot(x,y(:,1))
Functions:
function [dy]=hw7_24p16ydxn(x,y)
E=200*10^9;%in Pa
I=30000*10^(-8);%m^4
w=15*10^3;%N/m
L=3;%m
%x=[0 L];
%y=[0 0];
dy=[y(2);
(w*L*x-w*x^2)/(2*E*I)];
end
function [r]=hw7_24p16res(za)
[x,y]=ode45(@hw7_24p16dydxn,[0 L],[0 za]);
r=y(end,1)-0;
HELP!
darova on 13 Jan 2020
It means that function with this name doesn't exist
Undefined function 'hw7_24p16dydxn' for input arguments of type 'double'.
Look
function [dy]=hw7_24p16ydxn(x,y)

Jyotsna Talluri on 17 Jan 2020
You have defined a function with function name hw7_24p16ydxn and you are calling a function 'hw7_24p16dydxn' which does not exist