Re: default options, OptionsPattern[], and FilterRules[]

*To*: mathgroup at smc.vnet.net*Subject*: [mg106482] Re: default options, OptionsPattern[], and FilterRules[]*From*: dh <dh at metrohm.com>*Date*: Thu, 14 Jan 2010 05:47:56 -0500 (EST)*References*: <hik947$6qo$1@smc.vnet.net>

Hi Roman, the simplies way to do what you want is to specify: SetOptions[Plot,PlotRange->{-5,5}] If you nevertheless want to write your own function, you must not forget to give the default options in the plot command: Options[myplot] = {PlotRange -> {-5, 5}}; myplot[F_, opts : OptionsPattern[]] := Plot[F, {x, -1, 1}, (Evaluate[ Join[FilterRules[{opts}, Options[Plot]], Options[myplot]]])] myplot[x] Daniel Roman wrote: > dear group, > I am trying to set up a plotting function which has a different > default behavior than the standard one. Here's a simple example: > > Options[myplot] = {PlotRange -> {-5, 5}}; > myplot[F_, opts : OptionsPattern[]] := > Plot[F, {x, -1, 1}, Evaluate[FilterRules[{opts}, Options[Plot]]]] > > What I would like to achieve with this is that when I don't specify > the PlotRange option, as in > myplot[Sin[x]] > then I would get a plot with a default plot range of {-5,5}. > Unfortunately this does not work, since the call to FilterRules[] does > not access the default rules defined in Options[myplot], but only > those options explicitly specified in opts (i.e. none at all in this > call example). > > Since this seems like such a standard use of the Options framework of > Mathematica, I would expect there to be pre-defined functionality for > what I am trying to achieve. Of course I can manually merge the > contents of the opts variable with those of Options[myplot] and > eliminate duplicates, but I'd like to avoid such hacks if possible. > > Do you know a simple solution for this problem? > Thanks! > Roman. >