densityplot requires an expression or function as its argument. 

Is there any way to trick maple into using a list of points?

Suppose I set

a:=plot(x^2) or some other complicated expression, but just for simplicity sake

Then I go ahead fill up a worksheet then change the a to b in the same line and alter the expression for variable b (because I didn't want to type out a new line for the variable)

How do I recall what I've set a equal to? 

eval(a,1) - just returns the plot and    print(a,1) - returns PLOT(...),1

I think there's a way but I can't recall.  Can someone point me in the right direction?

When rotating any 3dplot, for axes=boxed, how can I stop the tickmark axes from jumping around to different edges of the box?

A small glitch

with(plots):
pointplot3d({[2,3,4],[1,2,3],[4,5,6]},symbol=box,axes=boxed)

The third point is missing from the plot however if I use axes=normal all three points are displayed but when the boxed option is enabled the point [4,5,6] is not displayed. 

It seems the autoscaling undercuts the last point and so is out of view of the plot.  In order to have the 3rd point visible (it is there) we need to use the view=[ xmin..xmax,ymin..ymax,zmin..zmax ] option.

I have a large number of lists labelled L1, L2, L3 ...etc.

I want to determine the number of elements in each list.  If I had labelled my lists L(1), L(2), L(3) ... I would easily have been able to pull out the number of elements with sequence

seq(nops(L(i)),i=1..3);

nops doesn't allow multiple arguments.  Is there any way I can use seq on the lists L1, L2, L3, ... etc  In other words, how can I have a two letter variable and get maple to vary the 2nd variable?