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Re: Joining points of ListPlot

  • To: mathgroup at smc.vnet.net
  • Subject: [mg117320] Re: Joining points of ListPlot
  • From: DrMajorBob <btreat1 at austin.rr.com>
  • Date: Tue, 15 Mar 2011 06:03:45 -0500 (EST)

y-values are mixed in the same List, you mean... not an Array... and the  
x-values are not with them?

Bobby

On Mon, 14 Mar 2011 05:57:45 -0500, Antonio Mezzacapo  
<ant.mezzacapo at gmail.com> wrote:

> Tha problem is that all points are on the same array, and I don't know  
> the
> functional form they have, so i can't separate the two arrays like you  
> did
> in your third example.
> It's like having Sin and Cos points on the same array, but they are not  
> Sin
> and Cos, and I don't know their analytic form!
>
> AM
>
> 2011/3/13 Michael Stern <nycstern at gmail.com>
>
>> 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
>>
>> Sent from a mobile device.
>>
>> On Mar 13, 2011, at 8:24 AM, 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>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


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