isstr is obsolete

[Mike G]

Greetings,

After finally successfully downloaded Octave and installing it, I am trying it out – carefully.

I am going through the installed manual Octave.pdf page by page. Seems really useful so far.

I am on page 8, the paragraph “Producing Graphical Output”.

It talks about a graphical interface – does it describe the graphical interface, where to get it, and how to use it later in the manual?

In the meantime,  am using the command line interface, since that was what was described in the beginning of the manual.

I run the program as described in the earlier paragraphs, then do the plot. I get back an error /notifier message. I have no idea how to implement the suggestion.

Here is the complete text of the operation:

 

octave:11>  function xdot = f (x, t)

>  r = 0.25;

>  k = 1.4;

>  a = 1.5;

>  b = 0.16;

>  c = 0.9;

>  d = 0.8;

>  xdot(1) = r*x(1)*(1-x(1)/k) - a*x(1)*x(2)/(1 + b*x(1));

> xdot(2) = c*a*x(1)*x(2)/1 + b*x(1) - d*x(2);

> endfunction

octave:12> x0 = [1; 2];

octave:13> t = linespace (0, 50, 200)';

error: `linespace' undefined near line 13 column 5

octave:13> t = linspace (0, 50, 200)';

octave:14> x = lsode ("f", x0, t);

octave:15> plot (t, x)

warning: isstr is obsolete and will be removed from a future version of Octave,

please use ischar instead

octave:16>

 

So, how do I use the different function called by plot? Do I have to do an edit, then recompile Octave?

Thanks.

 

Mike G.