Re: Why don't my plots appear? My 5.2 code no longer works correctly in 6.0

*To*: mathgroup at smc.vnet.net*Subject*: [mg89367] Re: [mg89326] Why don't my plots appear? My 5.2 code no longer works correctly in 6.0*From*: "Charlie Brummitt" <cbrummitt at wisc.edu>*Date*: Sat, 7 Jun 2008 02:59:05 -0400 (EDT)*References*: <200806061044.GAA24071@smc.vnet.net>

The Print command is what I need! Thanks for all the kind and helpful replies. -Charlie On Fri, Jun 6, 2008 at 7:36 AM, Murray Eisenberg <murray at math.umass.edu> wrote: > You'll probably get zillions of responses to your question. > > The treatment of Plot and related functions has changed with version 6: the > graphic created is no longer a side-effect of evaluating the function, but > rather the actual, direct RESULT of the function. (In Mathematica 5 and > before, the display was a side-effect whereas the direct result was a > -Graphics- object.) > > A consequence is that following a Plot with a semi-colon now has EXACTLY > the same effect of following any other command with a semi-colon: it > suppresses the result. More precisely, it produces a Null result, which by > default is not shown in any way. > > In general, a semi-colon is used to separate the parts of a compound > expression, for example: > > a = 2; Plot[Sin[a x], {x, 0, Pi}]; "Hello, world!" (* NO! *) > > has result the string 'Hello, world!. And indeed in Mathematica 6 you the > semi-colon after the Plot expression appears in red to warn you. To make > the plot appear, use Print: > > a = 2; Print[Plot[Sin[a x], {x, 0, Pi}]]; "Hello, world!" (* Yes *) > > Note this has nothing to do, per se, with Modules -- just compound > expressions in general. > > > > Charlie Brummitt wrote: > >> Hello, >> I am running into difficulties with Plot. Some code of mine that worked in >> 5.2 no longer works correctly in 6.0.2.0. Specifically, no plots appear >> whenever Plot (or Plot3D or DensityPlot or ListPlot) is called within a >> function that I have defined. >> >> Here is a closely related question: What does the red semicolon ";" mean >> at >> the end of "Plot[ ... ];"? Why is it red? In 5.2, placing a semicolon at >> the >> end of Plot[] allowed me to output a plot in the middle of a computation, >> without halting the computation. Now I can no longer seem to output a plot >> in the middle of a long computation. (I only see the output of Print[] >> commands.) I must be able to see these plots during long computations, >> like >> I was able to in 5.2. >> >> What's wrong? Can anyone please help? >> >> Thanks, >> >> Charlie >> >> >> > -- > Murray Eisenberg murray at math.umass.edu > Mathematics & Statistics Dept. > Lederle Graduate Research Tower phone 413 549-1020 (H) > University of Massachusetts 413 545-2859 (W) > 710 North Pleasant Street fax 413 545-1801 > Amherst, MA 01003-9305 >

**References**:**Why don't my plots appear? My 5.2 code no longer works correctly in 6.0***From:*"Charlie Brummitt" <cbrummitt@wisc.edu>