MathGroup Archive 2007

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Plot a number line

  • To: mathgroup at smc.vnet.net
  • Subject: [mg79744] Re: [mg79687] Plot a number line
  • From: Selwyn Hollis <selwynh at earthlink.net>
  • Date: Fri, 3 Aug 2007 06:28:42 -0400 (EDT)
  • References: <200708020741.DAA00009@smc.vnet.net>

Here's one possibility, but you have to fiddle with the endpoints of  
the arrow to make them coincide with the axis endpoints.

Plot[Infinity, {x, -11, 11},
  Axes -> {True, False},
  Ticks -> {Range[-10, 10], {}},
  AspectRatio -> Automatic,
  Epilog -> {Arrowheads[{-.033, .033}], AbsoluteThickness[.5],
    Arrow[{{-11.5, 0}, {11.5, 0}}]}]

So I decided to build it from scratch:

axisPlot[a_, b_, incr_: 1] := Show[
   (* minor ticks *)
   If[(b - a)/incr < 15,
    Graphics[{Gray,
      Table[Line[{{x, 0}, {x, .005 (b - a)}}], {x, a, b, incr/ 
10}]} ], {} ],
   (* major ticks *)
   Graphics[Table[Line[{{x, 0}, {x, .01 (b - a)}}], {x, a, b, incr}] ],
   (* tick labels *)
   Graphics[Table[Text[Chop[x], {x, -.025 (b - a)}], {x, a, b, incr}] ],
   (* double-headed arrow *)
   Graphics[{Arrowheads[{-.033, .033}], AbsoluteThickness[.5],
     Arrow[{{a - .067 (b - a), 0}, {b + .067 (b - a), 0}}]} ],
   Axes -> None,  AspectRatio -> Automatic]

axisPlot[0, 1, .1]

axisPlot[-10,10]


-- Selwyn Hollis



On Aug 2, 2007, at 3:41 AM, Diana wrote:

> Math folks,
>
> I am trying to plot just an x axis number line with varying end
> points.
>
> For example, I would like a number line with starting and ending
> arrows pointing to negative and positive infinity, with the numbers
> -10, -9, ..., 8, 9, 10 printed on the line. I would like just the tick
> marks at integer markings. This is meant to be a template for students
> to graph the solution set to an inequality on it.
>
> Can someone help?
>
> Thanks,
>
> Diana M.
>
>



  • Prev by Date: Re: Differentiation w.r.t. elements of lists
  • Next by Date: Memmory issue while batch exporting graphics
  • Previous by thread: Plot a number line
  • Next by thread: Re: Plot a number line