Error using==> nargin

Hi,

I am a new user to mathlab, and trying to solve 11 simultaneous 1st order differential equation:

Here is the M-file :

funtion dxdt=anu(t,x)
%x(1)=xA, x(2)=xB, x(3)=xC, x(4)=xD, x(5)=xE, x(6)=xF, x(7)=xG, x(8)=xH,
%x(9)=xI, x(10)=xJ, x(11)=xK
global kg ka kb kc kd Z
dxdt=[-kg/Z*(x(2)+x(4)+x(7)+x(10)+x(11)); 1/Z*(kg*x(1)-ka*x(2)); 1/Z*ka*x(2); 1/Z*(kg*x(1)-kb*x(4)); 1/Z*(kb*x(4)-2*kd*x(5)); 1/Z*kd*(x(5)+x(8));1/Z*(kg*x(1)-kc*x(7)); 1/Z*(kc*x(7)-2*kd*x(8)); 1/Z*kd*(x(5)+x(8)); 1/Z*kg*x(1); 1/Z*kg*x(1)];

This is the call function:

>> clf
>> global kg ka kb kc kd Z
>> kg=0.03118;
>> ka=0.0042;
>> kb=0.000083;
>> kc=0;
>> kd=0.00025;
>> Z=4.056*10^-4;
>> tspan=[0:10:240];
>> x0=[1 0 0 0 0 0 0 0 0 0 0];
>> [t,x]=ode45('anu',tspan,x0);

Here is the error i got:

??? Error using ==> nargin
anu is a script.

Error in ==> funfun\private\odearguments at 80
    if (nargin(ode) == 2)           

Error in ==> ode45 at 173
[neq, tspan, ntspan, next, t0, tfinal, tdir, y0, f0, odeArgs, ...

Somebody please help, i am new to mathlab so please simply.. Thanks

Answer 1

[Walter Roberson]

Your function anu starts with the word

funtion

which is missing the 'c'.

[Jan]

After eating a soup with noodles shaped like characters ("Buchstabennudeln"), a friend of mine told me: "Jan, da liegt ein C auf dem Tisch" (there lies a C on the table). It was distusting, because I understood: "da liegt ein Zeh auf dem Tisch" (the lies a toe on the table).

I wish you and all readers a scary halloween.

Answer 2

[Walter Roberson]

Earlier in your path, you must have another anu.m file that is a script (no "function" line)

Try

which -all anu

and compare that to the anu that you are expecting to be invoked.

Note: if the anu function that you show above is stored in a file other than anu.m then MATLAB will not be able to find the right file when you pass 'anu' as a quoted string to ode45: passing as a quoted string always forces MATLAB to feval() the name in the base workspace. Using function handles such as @anu is more likely to work in such a situation.

Answer 3

[Raphel]

Thanks for the quick response, anu was new m-file, i didnt have it earlier. Its stored in anu.m. can you explain how to use @anu??

[Walter Roberson]

Change

[t,x]=ode45('anu',tspan,x0);

to

[t,x]=ode45(@anu,tspan,x0);

[Walter Roberson]

Note: if there is *any* executable line in anu.m before the "function" line, then the file would be considered a script rather than a function. You need it to be a function.

[Dennis]

Walter i got the error after following up on your recomendations:

Warning: feval on script names will not work, or may work differently,

in a future version of MATLAB. To make your code insensitive to any change

and to suppress this warning message:

- Either change the script to a function.

- Or use eval instead of feval.

The script file in question is anu.

> In funfun\private\odearguments at 110

In ode45 at 173

??? Attempt to execute SCRIPT anu as a function.

Error in ==> funfun\private\odearguments at 110

f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.

Error in ==> ode45 at 173

[neq, tspan, ntspan, next, t0, tfinal, tdir, y0, f0, odeArgs, ...

Answer 4

[Dennis]

Hi Walter, When did: [t,x]=ode45(@anu,tspan,x0); i got error: Warning: feval on script names will not work, or may work differently, in a future version of MATLAB. To make your code insensitive to any change and to suppress this warning message: - Either change the script to a function. - Or use eval instead of feval. The script file in question is anu. > In funfun\private\odearguments at 110 In ode45 at 173 ??? Attempt to execute SCRIPT anu as a function.

Error in ==> funfun\private\odearguments at 110 f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.

Error in ==> ode45 at 173 [neq, tspan, ntspan, next, t0, tfinal, tdir, y0, f0, odeArgs, ... Please help!

Answer 5

[Dennis]

Walter, Thank you soo much.. Dennis K

[pavitra ramdas]

Did it work? I have the same problem. I executed it as a function and I am still getting the same error

Answer 6

[pavitra ramdas]

 I have the same problem. I executed it as a function and I am still getting the same error