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: [mg89370] Re: Why don't my plots appear? My 5.2 code no longer works correctly in 6.0
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Sat, 7 Jun 2008 02:59:38 -0400 (EDT)
On 6/6/08 at 6:44 AM, cbrummitt at wisc.edu (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?
The manner in which graphics are generated changed from version
5 to version 6. In version 6 terminating any statement that
generates graphics with a semicolon causes display of the
graphics to be suppressed. The red semicolon is a warning to you
the graphics will not display.
You have a couple of ways to get plots to display when created
as part of a long computation. One would be to use a Print
statement. For example,
x = a + b;
Print@Plot[x, {x, 0, 1}];
y = x;
or assign use a variable to capture the graphic and display it
later. That is,
x = a + b;
z = Plot[x, {x, 0, 1}];
y = x;
Show[z]