Thanks, Scott.  I don't believe that complexplot3d does the same thing as I need.  I believe that it plots |f(z)| over the given 2D domain. 

The good news is that I have figured out what was wrong.  The option in plotcompare that allows one to plot just the real and imaginary parts of a single function, as opposed to two functions, is expression_plot.  The mistake I was making was this:  When one is writing a command, one is in MATH input mode.  The underscore character is reserved in this mode.  It is the shortcut for subscript.  Thus, when I typed underscore, I was actually inputting a subscripted hyphen.  These look the same to the untrained eye. (I have untrained eyes.)  What I now know that I needed to do was use the escape character "\" before the underscore actually input an underscore. 

If Maple programmers are scanning these posts, you folks might want to avoid, in future versions, having reserved characters like underscore as part of an argument for a command. 

Now, I have a new question:  If one only wants the real and imaginary parts of a single function, must one type the same function in twice?  It seems that way.  The plotcompare command wants its first two arguments to be complex functions.  Is there any way around this?   (Mind you, this is only an inconvenience, not an impediment.) 

Thank you, Alex, but this is not quite what I meant.  In plotcompare, one gets a 3D surface plot of the real part and the imaginary part of the graph of a complex function.  That is, a specified portion of the 2D complex plane is the domain and the range is Re(f(z)) in one panel and Im(f(z)) in the other. 

The problem is, plotcompare does this for two complex functions f(z) and g(z).  I would like to display only the real and imaginary plots (precisely as plotcompare does this) but only for a single function. 

The options listed in Help say that expression_plot is the way to do this but I get an error when I try this.  I would like to see this typed exactly as needed. 

Thanks.