0 个投票

%I have this function script, created and saved with no mistakes. When I try to solve the ODE, using ode45 it does not work, I get this:
Error using feval
Undefined function 'govequ' for input arguments of type
'double'.
Error in odearguments (line 87)
f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to
yp0.
Error in ode45 (line 113)
[neq, tspan, ntspan, next, t0, tfinal, tdir, y0, f0,
odeArgs, odeFcn, ...
Here, the function script:
function y_dot = govequ(t,y)
y_dot = -t^2-4*y;
end
And here the command I use to solve it:
[ts,ys] = ode45(@govequ, [0,10], 1)

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Walter Roberson
Walter Roberson 2016-2-19
Your function govequ is not in govequ.m somewhere on the MATLAB path.

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 采纳的回答

Star Strider
Star Strider 2016-2-19

1 个投票

This works for me (in R2015a):
govequ = @(t,y) -t.^2-4*y;
[ts,ys] = ode45(govequ, [0,10], 1);
figure(1)
plot(ts, ys)
grid

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I need a function file, anyways, I saw the problem. Thank you
Star Strider
Star Strider 2016-2-20
My pleasure.

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