Re: help with graphics command

*Subject*: [mg2882] Re: [mg2874] help with graphics command*From*: twj (Tom Wickham-Jones)*Date*: 4 Jan 1996 04:10:42 -0600*Approved*: usenet@wri.com*Distribution*: local*Newsgroups*: wri.mathgroup*Organization*: Wolfram Research, Inc.*Sender*: mj at wri.com

>I am trying to plot a sine wave with the middle portion grayed out. The Plot command seems >like the way to go, but I can't figure out how to get my rectangle to come out >in like a GrayLevel[0.5]. (See syntax below) Is it possible to adjust the >shade of gray on the rectangle? I'm working off the example on page 413 of >the mathematica book. > >If it is not possible to adjust the shade used with this command, can you suggest an > alternate way? > > >Plot[Sin[x]*50, {x, 0, 2Pi}, Prolog -> Rectangle[Scaled[{0.02, 0.25} ] , > Scaled[{1, 0.75}] ]] The argument of the Prolog option can be any collection of graphics primitives and style directives. If there are more than one they must be placed in a list. Plot[Sin[x]*50, {x, 0, 2Pi}, Prolog -> {GrayLevel[0.5], Rectangle[Scaled[{0.02, 0.25} ] , Scaled[{1, 0.75}] ]}] With this the GrayLevel[0.5] is also used to draw the plot. To prevent the plot from being colored the Prolog argument can be placed in one more level of lists. Plot[Sin[x]*50, {x, 0, 2Pi}, Prolog -> {{GrayLevel[0.5], Rectangle[Scaled[{0.02, 0.25} ] , Scaled[{1, 0.75}] ]}}] In this case using Frame axes may improve the picture. Plot[Sin[x]*50, {x, 0, 2Pi}, Frame -> True, Axes -> False, Prolog -> {{GrayLevel[0.5], Rectangle[Scaled[{0.02, 0.25} ] , Scaled[{0.98, 0.75}] ]}}] Tom Wickham-Jones WRI