Re: Graphics and DisplayFunction
- To: mathgroup at smc.vnet.net
- Subject: [mg98250] Re: Graphics and DisplayFunction
- From: David Bailey <dave at removedbailey.co.uk>
- Date: Fri, 3 Apr 2009 04:39:31 -0500 (EST)
- References: <gqsn9m$3tr$1@smc.vnet.net> <gr21l6$lq8$1@smc.vnet.net>
replicatorzed at gmail.com wrote:
> Thanks for the answer Szabolcs,
>
> Ok, so if I understand it correctly then by using explicit
> DisplayFunctions, I display the *thing*, that is the side effect of
> the actual function. Obviously only things that are enclosed in Show
> can be thus displayed with DisplayFunctions, and - however it's just a
> guess - the various plot functions all utilize an internal Show which
> encloses their internal graphics. Thus - secondarily - DisplayFunction
> can be used with plotting functions as well. But then I simply don't
> understand why DisplayFunction is an option for Graphics? Neither
>
I would forget about the DisplayFunction option - it is more or less
obsolete. Just think of graphics as output - just like numbers or equations.
If you do a calculation, and then as the last step generate a graphical
output (either explicitly with Graphics, or indirectly using Plot (say),
then providing you don't terminate that command with a semicolon, you
will get your graphical output, for example:
xx = 10;
yy = 20;
Graphics[{Line[{{-xx/2, 0}, {xx/2, 0}}],
Line[{{0, -yy/2}, {0, yy/2}}]}]
If, however, you want to go on and calculate something else (or make
another graph), simply print your graphical output (again, exactly as
you would for text):
xx = 10;
yy = 20;
Print[Graphics[{Line[{{-xx/2, 0}, {xx/2, 0}}],
Line[{{0, -yy/2}, {0, yy/2}}]}]];
Print["Something else ",Sqrt[xx]];