why is it not working?

%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)

[Walter Roberson]

Your function govequ is not in govequ.m somewhere on the MATLAB path.

Answer 1

[Star Strider]

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

[George Schwarzenneger]

I need a function file, anyways, I saw the problem. Thank you

[Star Strider]

My pleasure.