Re: Joining points of ListPlot
- To: mathgroup at smc.vnet.net
- Subject: [mg117322] Re: Joining points of ListPlot
- From: DrMajorBob <btreat1 at austin.rr.com>
- Date: Tue, 15 Mar 2011 06:04:07 -0500 (EST)
A short, simple example is worth a thousand words. You're still not making
yourself clear.
Bobby
On Mon, 14 Mar 2011 06:01:17 -0500, Antonio Mezzacapo
<ant.mezzacapo at gmail.com> wrote:
> Thank you for answering.
>
> 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
>> >
>>
--
DrMajorBob at yahoo.com