Re: Trouble installing control toolbox

[Ben Abbott]

On Dec 13, 2012, at 10:11 PM, Michael Noone wrote:

> OK - more attempts. I noticed some interesting things. It gives me a warning 
> "warning: X11 DISPLAY environment variable not set". I tried loading gnuplot 
> and then fltk, and the latter operation caused an error. Finally, after 
> switching to fltk and doing a close all, I caused Octave to crash.
> 
> I checked with Cygwin and I have "libfltk 1.1" installed already.
> 
> Any of this mean anything to anybody? :) I'm including the full output below, 
> sorry for the huge paste. Thanks!!
> 
> $ octave
> ...
> warning: X11 DISPLAY environment variable not set
> octave:1> pkg load control
> octave:2> pkg load gnuplot
> octave:3> pkg load fltk
> error: package fltk is not installed
> error: called from:
> error:   /usr/share/octave/3.6.2/m/pkg/pkg.m at line 2134, column 11
> error:   /usr/share/octave/3.6.2/m/pkg/pkg.m at line 401, column 7
> octave:3> A = tf(1, [1 2 3])
> 
> Transfer function 'A' from input 'u1' to output ...
> 
>             1
>  y1:  -------------
>       s^2 + 2 s + 3
> 
> Continuous-time model.
> octave:4> bode(A)
> +-------------------------------Bode Diagram of 
> A------------------------------+
> |    Magnitude [dB]                                                           
>  |
> |     -10 ++----+---+-+-+-+++++-----+---+--+-++-++++-----+--+--+-++-++++      
>  |
> |     -20 ++..................+.....+++++++........+..................++      
>  |
> |     -30 ++..............................++++++......................++      
>  |
> |     -40 ++...................................+++++++................++      
>  |
> |     -50 ++.........................................+++++++..........++      
>  |
> |     -60 ++...............................................++++++.....++      
>  |
> |     -70 ++..................+....................+............++++++++      
>  |
> |     -80 +-1---+---+-+-+-+++++0----+---+--+-++-++++1----+--+--+-++-++++2     
>  |
> |        10                  10                   10                  10      
>  |
> |   Phase [deg]                                                               
>  |
> |       0 ++----+---+-+-+-+++++-----+---+--+-++-++++-----+--+--+-++-++++      
>  |
> |     -20 ++.....++++++++++++++....................+..................++      
>  |
> |     -60 ++.................+++++....................................++      
>  |
> |     -80 ++.....................+++..................................++      
>  |
> |    -100 ++.......................++++...............................++      
>  |
> |    -140 ++..........................+++++...........................++      
>  |
> |    -160 ++..................+...........+++++++++++++++.............++      
>  |
> |    -180 +-1---+---+-+-+-+++++0----+---+--+-++-++++1----+--+--+-++-++++2     
>  |
> |        10                  10                   10                  10      
>  |
> +------------------------------------------------------------------------------+
> octave:5> graphics_toolkit
> ans = gnuplot
> octave:6> close all
> octave:7> graphics_toolkit fltk
> octave:8> bode(A)
> Can't open display:
> terminate called after throwing an instance of 'std::length_error'
>   what():  basic_string::_S_create
> Aborted

Looks like you don't have x11 installed?

Try using gnuplot's Windows terminal instead.

close all
graphics_toolkit gnuplot
setenv GNUTERM windows
plot (rand (3))

... And you'll either get a gnuplot window or an error.

Ben