more than 2 y axes in one plot

[Wolfgang Schechinger]

Dear Experts,

I want to plot 4 curves with a common x-axis into one plot (a chromatogram with 
several curves: 2x UV, pH, conductivity. With largely different y scales, so 
I'd like to have several y axes).

I came across addaxis 
(http://www.mathworks.com/matlabcentral/fileexchange/9016), but with the 
example code in addaxis.m, I get errors:

GNU Octave, version 3.6.2
Octave was configured for "i686-pc-mingw32".

[snip]

octave-3.6.2.exe:3> x = 0:.1:4*pi;
octave-3.6.2.exe:4> plot(x,sin(x));
octave-3.6.2.exe:6>  addaxis(x,sin(x));
error: addaxis: A(I): index out of bounds; value 3 out of bound 2
error: called from:
error:   C:\Program Files (x86)\Octave-3.6.2\share\octave\3.6.2\m\wo\addaxis\add
axis.m at line 46, column 3


It seems that some matlab plotting functions originally needed to be modified 
(the readme asks to replace some matlab files by code included in the package), 
but that seems to be not easy or impossible, without knowing about Octave's 
internals.

Has anyone by chance solved this problem or knows about another solution for my 
initial plotting problem?

Thanks for your help and best regards!

Wo