issues with 'orbits'



Hello,
 I have been playing with the 'orbits' program in the dynamics package.

Here are some issues.    All are with maxima version 5.19.2

1. In Win XP or Vista, the command
 orbits(r*x*(1-x),.2,100,200,[r,3,4,.1]);

takes about 5 seconds to get to  "Graph passed to plot2d"   Then it 
takes about another minute or so to actually produce the plot.   This is 
on a fast laptop.  I takes considerable longer on the laptops my 
students have.

If one adds the option as in
orbits(r*x*(1-x),.2,100,200,[r,3,4,.1],[plot_format, openmath]);

then the plot  is produced almost 2 or 3 seconds after the words "Graph 
passed to plot2d" 

So, it seems that the interface to gnuplot has some problems.

2. In linux (Fedora Core 8) this problem does not occure.  The plot is 
drawn soon after the words "Graph passed to plot2d"  appear.

3. In linux ( don't know about WinXP) there is a problem with the 
command 'orbits' if the package 'dynamics' is already loaded:

(%i3) build_info();

Maxima version: 5.19.2
Maxima build date: 13:10 9/20/2009
host type: i686-pc-linux-gnu
lisp-implementation-type: CMU Common Lisp
lisp-implementation-version: 19d Fedora release 5.fc8 (19D)

(%o3)
(%i4) display2d: false;

(%o4) false
(%i5) load(dynamics);

(%o5) "/usr/local/share/maxima/5.19.2/share/dynamics/dynamics.mac"
(%i6) orbits(r*x*(1-x),.2,100,200,[r,3,4,.1]);

Graph passed to plot2d...
Improper name or value in functional position:
errexp1
#0: 
orbits(f=r*(1-x)*x,y0=0.2,n1=100,n2=200,domain=[r,3,4,0.1],options=[])(dynamics.mac 
line 367)
 -- an error.  To debug this try debugmode(true);

4. In general, replotting in the 'openmath' window has many bugs.  Try 
zooming, unzooming, or resizing to the whole screen and replotting for 
instance.

-sen

P.S. Thanks to Jaime for the dynamics package