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Re: Re: How to combine graphics pimitives and

• To: mathgroup at smc.vnet.net
• Subject: [mg107065] Re: [mg107024] Re: [mg107011] How to combine graphics pimitives and
• From: Tomas Garza <tgarza10 at msn.com>
• Date: Tue, 2 Feb 2010 03:25:41 -0500 (EST)

Thanks, Murray. May I point out a couple of typos in your message: in

>    Draw2D[{
>            Draw[Sin[x],{x,-Pi,Pi}],
>            {Red,Line[points]}
>            },
>            Axes->True]

should be {Red, ComplexLine[points]}
and in

    > Draw2D[{Draw[Sin[x],{x,-Pi,Pi}],Red,ComplexLine[pts]},Axes->True]

should be ComplexLine[points]

Tomas

> Date: Mon, 1 Feb 2010 06:09:40 -0500
> From: murray at math.umass.edu
> Subject: [mg107024] Re: [mg107011] How to combine graphics pimitives and Plot function?
> To: mathgroup at smc.vnet.net
>
> Trying to do this kind of thing using Mathematica's built-in paradigm
> for graphics causes trouble for many beginners.
>
> Here's one way.  (I changed the x-domain because otherwise the random
> polygon collapses to a small blur.)
>
>    points = RandomReal[{-1,1},{100,2}];
>    Show[{
>          Plot[Sin[x],{x,-Pi,Pi}],
>          Graphics[{Red,Line[points]}]
>         }]
>
> The Graphics has to apply only to the {Red,Line[points]}, as the result
> of the Plot expression is already a Graphics object.
>
> You don't need the Axes->True option, as that's the default for Plot.
> However -- and this really drives folks nuts -- if you reverse the order
> of the Graphics objects...
>
>    Show[{Graphics[{Red,Line[points]}], Plot[Sin[x], {x,-Pi,Pi}]}]
>
> ... then the axes disappear and you have to insert the Axes->True option
> within the Graphics[{Red,Line[points]}] expression:
>
>    Show[{Graphics[{Red, Line[points]}, Axes -> True],
>          Plot[Sin[x], {x, - Pi, Pi}]}]
>
> No wonder this sort of thing gives so much trouble!
>
> But a much simpler way to do the whole thing is to use the different
> paradigm that's supplied by David Park's Presentations application:
>
>    Needs["Presentations`Master`"]
>
>    points = RandomReal[{-1,1},{100,2}];
>
>    Draw2D[{
>            Draw[Sin[x],{x,-Pi,Pi}],
>            {Red,Line[points]}
>            },
>            Axes->True]
>
> Notice that the Axes->True option is for the entire Draw2D expression;
> this means you'll get axes without any further ado no matter in what
> order you list the two objects, Draw[Sin[x]....] and {Red,Line[points]}.
>
> I've deliberately pretty-printed both versions in order to emphasize the
> structure of the overall expression.
>
> In the version done with Presentations, notice that all the different
> objects to be drawn (by the Draw2D) are "at the same level", one after
> the other, so that there's no need for wrapping the {Red,Line[points]
> expression with Graphics.
>
> With Presentations, moreover, you don't have to explicitly form pairs of
> reals as coordinates of the points, but may instead form complex numbers
> directly and plot a "complex line" whose vertices are the corresponding
> complex points:
>
>    points = RandomComplex[{-1 - I, 1 + I}, 100];
>    Draw2D[{Draw[Sin[x],{x,-Pi,Pi}],Red,ComplexLine[pts]},Axes->True]
>
>
> On 1/31/2010 7:53 AM, a boy wrote:
> > points = RandomReal[{-1, 1}, {100, 2}]
> > Graphics[{Red, Line[points], Plot[Sin[x], {x, -10 Pi, 10 Pi}]},
> >   Axes ->  True]
>
> --
> 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
>

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  • Re: Re: Re: How to combine graphics
    • From: Murray Eisenberg <murray@math.umass.edu>