Re: A Question About Directive

*To*: mathgroup at smc.vnet.net*Subject*: [mg111107] Re: A Question About Directive*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Tue, 20 Jul 2010 03:45:19 -0400 (EDT)

In some situations, using Directive[opt1,opt2] instead of {opt1,opt2} can make code easier to read by avoiding nested parentheses. Compare, for example: Plot[{Sin[x],Cos[x]},{x,0,Pi},PlotStyle-> {Directive[Thick,Red],Directive[Thick,Dashed,Blue]}] Plot[{Sin[x], Cos[x]}, {x, 0, Pi}, PlotStyle -> {{Thick, Red}, {Thick, Dashed, Blue}}] On 7/19/2010 2:10 AM, Kevin J. McCann wrote: > I have noticed the use of Directive in some of the graphics examples > from Bob Hanlon, David Park, and others. I am curious about this > command, since it does not appear to do much that is new. For example, > here is an example from the Help on Directive: > > Graphics[{Directive[Red, Thick], Circle[], > Directive[Blue, Opacity[0.5]], Rectangle[{0, -1}, {2, 1}]}] > > However, if I change to this, I get the same thing: > > Graphics[{Red, Thick, Circle[], Blue, Opacity[0.5], > Rectangle[{0, -1}, {2, 1}]}] > > So, what is the benefit of Directive? > > Thanks, > > Kevin > -- 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