Hi Prof. Feissner,

I suspect that Options > Autoscale New Plots is checked on some of the
machines.  Try unchecking it on all machines, replotting using Insert >
Plot and see if the plots are consistent.  The following excerpt from
the online help explains more about this command.

-----------------------------------------------------------------------
Autoscaling is helpful to frame a plot so it lies within the plot
region.  If automatic scaling is on, before an expression is plotted, it
is evaluated at several sample points to estimate the range of values
the expression assumes over the horizontal plot interval.  This estimate
is then used to adjust the vertical length and center of the plot region
so that the plot is properly framed.  Note that:

*       Some parts of an autoscaled plot may lie outside the vertical
plot region because only a sampling of data points is taken.

*       Autoscaling adjusts both the vertical length and center of the
plot region in order to autoscale the plot.

*       Autoscaling does not adjust the horizontal plot range.

--------------------------------------------------------------

Hope this helps,

Theresa Shelby
Texas Instruments

> -----Original Message-----
> From: DERIVE computer algebra system 
> [mailto:[log in to unmask]] On Behalf Of George Feissner
> Sent: Tuesday, September 28, 2004 9:42 AM
> To: [log in to unmask]
> Subject: question on space curves
> 
>     I've been graphing space curves for my calculus class and 
> have encountered an anomaly.  On a machine in one lab, I 
> enter the curve as a vector,  eg [t,t^2,t^3],  open a three-d 
> plot window,  click on INSERT, then on PLOT.  I get the 
> dialog box allowing me to enter minimum and maximum values of 
> the parameter  t  as well as the number of panels.  I then 
> get the plot as I requested it.  On a machine in a second 
> lab, the values I enter for minimum and maximum values of the 
> parameter as well as for the number of panels are ignored and 
> I get a graph apparently generated from some set of "default" 
> values.  Interestingly enough, the machine in my office 
> behaves in the manner of the first lab machine and the one on 
> my desk at home in the manner of the second.  Has anyone 
> encountered this?  Do we have two versions of DERIVE running? 
>  Is there some setting on one set of machines that can be 
> changed to eliminate the problem?  Thanks in advance.
> George F. Feissner
> Department of Mathematics
> SUNY at Cortland
> [log in to unmask]   
>