Re: Joining points of ListPlot

• To: mathgroup at smc.vnet.net
• Subject: [mg117281] Re: Joining points of ListPlot
• From: Michael Stern <nycstern at gmail.com>
• Date: Mon, 14 Mar 2011 05:57:23 -0500 (EST)

```Can you provide an example of your data? Sorting by the independent variable should give you the results you want, as in my third example.

MS

On Mar 13, 2011, at 8:24 AM, Antonio Mezzacapo <ant.mezzacapo at gmail.com> wrote:

>
> I don't have any functional form of this points. I have only this array of points. Points on this array should be distributed like two crossing functions as Sin[x] and Cos[x], but I don't know the functional form of these functions.
>
> All that I have is an array of points!
> Because of the fact that these points distribute on the x-y cartesian plane like two crossing functions, I cannot use "joined->true" because it gives me strange results.
>
> Thank you
> Antonio
>
> 2011/3/13 Michael Stern <nycstern at gmail.com>
> Antonio,
>
> Some points of your question are unclear, but perhaps this will cover all relevant cases.
>
> 1. If you have functions, the simplest way is:
>
> Plot[{Sin[x], Cos[x]}, {x, 0, 2*Pi}]
>
> 2. You refer to "joined points," however, which suggests that you may be dealing with lists of points rather than functions. If so, you can do the same thing as follows:
>
> (* creating the two lists *)
> s1 = Table[Sin[x], {x, 0, 2*Pi, .1}];
> c1 = Table[Cos[x], {x, 0, 2*Pi, .1}];
>
> (* plot *)
> ListPlot[{s1, c1}, Joined -> True]
>
>
> 3. You refer to the points not being ordered, from which I take that one or both of the lists of plots has cartesian coordinates, not ordered by the independent variable. In this case, you can use Sort or SortBy to put them in order.
>
> (* creating two cartesian lists, neither of which is 'ordered' by the definition above *)
> s2 = RotateLeft[Table[{x, Sin[x]}, {x, 0, 2*Pi, .1}]];
> c2 = RotateRight[Table[{x, Cos[x]}, {x, 0, 2*Pi, .1}]];
>
> (* plot by sorted versions of these unordered lists *)
> ListPlot[{SortBy[s2, First], SortBy[c2, First]}, Joined -> True]
>
>
> Does that help?
>
> Michael
>
>
> On Mar 13, 2011, at 6:25 AM, Antonio Mezzacapo wrote:
>
> > Hi,
> > here's my problem:
> >
> > I have an array of data depicting two crossing functions (let's say like
> > Sin[x] and Cos[x]). How can I arrange them and make a joined points plot,
> > that joins only points belonging to the same function?
> > I remember you that the points of the two crossing functions are on the same
> > array and they are non-ordered.
> >
> > Thank you
> >
> > Antonio Mezzacapo
> >
>

```

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