Integration code

[이태훈]

Hi.

I am relatively new to Octave and my problem is most likely rather trivial, so I apologise in advance.

I made a code for integrating a function. 

I use the code https://octave.org/doc/v5.2.0/Simple-Examples.html#Integrating-Differential-Equations from here. 

function x dot  =f(x,t)

   D  =1.1

    ka =3;

   z  =10

   umax=0.08

   km =3

   I0 =1

   xdot(1)= (-x(1).*(D)).+((umax.*((I0.*2.717^(-ka.*x(1)*z))./((I0.*(2.717^(-ka.*x(1)*z))).+km))).*x(1))

endfunction

>> x0=[1;2];

>> t= linspace (0,50,100)';

>> x= lsode ("f",x0,t);

But error appears:

warning: lsode: passing function body as a string is obsolete; please use anonymous functions

error: 'f' undefined near line 1 column 43

error: lsode: evaluation of user-supplied function failed

error: called from

    __lsode_fcn__to__ at line 1 column 41

Do you know what should I do for the anonymous function  ??? 

And how I define “f" ??? 

I tried to look the script on Octave, but couldn’t understand it. 

It would be nice if you show me some examples 

Best regards 

Tae hoon lee