Adding markers on the surface of a Plot3D?
- To: mathgroup at smc.vnet.net
- Subject: [mg89328] Adding markers on the surface of a Plot3D?
- From: AES <siegman at stanford.edu>
- Date: Fri, 6 Jun 2008 06:45:11 -0400 (EDT)
- Organization: Stanford University
I'd like to highlight the two mesh lines that pass through a certain
central point -- let's call it the point {xc,yc} -- on a Plot3D by
thickening those two lines relative to the other mesh lines, or giving
them a distinctive color, or . . .
Or put a dot on the surface at the point {xc, yc, f[xc,yc]} to identify
this location on the surface . . .
Or run a vertical "post" up through that point using something like
Line[{xc, yc, 0}, {xc, yc, 2*f[xc,yc]}}] (with the part of the post
below the surface not being seen if you look at the surface from
above) . . .
I think I've so far tested and confirmed every possible way in which
each of these tasks _can't_ be done . . .
[And would someone want to help me understand _why_ the
Show[ - - - - -] command (followed by a semicolon) no longer works, or
can no longer be used, as one of a sequence of multiple expressions
within a longer cell? And why it can't even have a semicolon following
it as the last line in a cell? I just can't envision the logic of why
this was a necessary (or optional?) interface design decision -- isn't
Show[---] an expression?]