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I have some data points in given below format:

data = {{0, 0}, {0.5, 2}, {1, 5}, {2, 8.5}, {4, 10}, {0, 0}, {0.5, 
4}, {1, 7}, {2, 9.5}, {4, 12}, {0, 0}, {0.5, 5}, {1, 9}, {2, 
12}, {4, 18}};

ListLinePlot[data

How to plot these data in ListLinePlot without joining the line from last data point to first one (highlighted by yellow square)?

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  • $\begingroup$ What code generated the plot? $\endgroup$
    – Coolwater
    Jan 14, 2018 at 11:32
  • $\begingroup$ ListLinePlot[data] $\endgroup$ Jan 14, 2018 at 11:33
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    $\begingroup$ That makes no sense. The maximal y-value in data is 10, whereas on the plot it's 19. $\endgroup$
    – Coolwater
    Jan 14, 2018 at 11:41
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    $\begingroup$ Please post the full code that gave your output. With the given data, we can get this. $\endgroup$
    – corey979
    Jan 14, 2018 at 12:07
  • $\begingroup$ Shall data describe a single curve or 3? (In the latter case, the three curves would be equal.) $\endgroup$ Jan 14, 2018 at 12:09

4 Answers 4

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ListLinePlot[Split[data, #2 =!= {0, 0} &], PlotMarkers -> Automatic]

myplot.jpeg

Edit

The problem with the 'real' data imported from drive.google.com/open?id=1uXuPcB-ibTS3Q7d4EDluyz-JF-wm_CLL is merely one of machine precision versus exact values for {0,0} - the y-values of each 'split point' are very close to but not exactly zero.

Mathematica has a very nice command, Chop, which 'replaces approximate real numbers in expr that are close to zero by the exact integer 0.", and one way of solving the problem is as follows:

ListLinePlot[Split[Chop[data, 0.0001], #2 =!= {0, 0} &], PlotMarkers -> Automatic]

mynewplot.jpeg

Data were imported with:

data = Import["glv.1to.5.txt", "Data"];
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  • $\begingroup$ Thanks it working on data that is given here, but it is not working on .txt imported data file? $\endgroup$ Jan 14, 2018 at 21:20
  • $\begingroup$ @GopalVerma Can you supply a copy of the .txt file? (and, if possible, the code you use to import). $\endgroup$
    – user1066
    Jan 14, 2018 at 23:26
  • $\begingroup$ Pls. find the link of data file. I am using Import[filename.txt,"Data".] command for importing the data file. drive.google.com/open?id=1uXuPcB-ibTS3Q7d4EDluyz-JF-wm_CLL $\endgroup$ Jan 15, 2018 at 16:52
  • $\begingroup$ Thanks,It is working. $\endgroup$ Jan 15, 2018 at 22:17
  • $\begingroup$ Can u suggest how to change the thickness of line joining the data point(or plot markers). $\endgroup$ Jan 20, 2018 at 16:08
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data = {{0, 0}, {0.5, 2}, {1, 5}, {2, 8.5}, {4, 10}, {0, 0}, {0.5, 4}, {1, 7}, {2, 9.5}, {4, 12}, {0, 0}, {0.5, 5}, {1, 9}, {2, 12}, {4, 18}};

By splitting the data separate curves are obtained

ListLinePlot[TakeList[data,
                      Length /@ Split[Module[{i = 0, prev = -∞},
                       Table[If[prev < (prev = j), i, ++i], {j, data[[All, 1]]}]]]]]

Alternatively:

(* positions where new curve start *)
pos = Position[UnitStep[Differences[data[[All, 1]]]], 0][[All, 1]]

ListLinePlot[TakeList[data,
                      Append[Differences[Join[{0}, pos]], UpTo[∞]]]]
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  • $\begingroup$ I think you meant Take[List ... ]. $\endgroup$
    – Themis
    Jan 14, 2018 at 14:02
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    $\begingroup$ @Themis No, TakeList is new in 11.2 $\endgroup$
    – Coolwater
    Jan 14, 2018 at 14:04
  • $\begingroup$ Thanks, But I don't have Math. 11.2 so can u suggest any other option for that. $\endgroup$ Jan 14, 2018 at 14:52
  • $\begingroup$ @Coolwater Good to know, I am still in 11.1.1. $\endgroup$
    – Themis
    Jan 14, 2018 at 15:07
  • $\begingroup$ @GopalVerma In older versions replace TakeList by Internal`PartitionRagged $\endgroup$
    – Coolwater
    Jan 14, 2018 at 15:20
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Does

ListLinePlot[Partition[data, Floor[Length[data]/3]]]

do what you seek for?

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  • $\begingroup$ Sorry,It is not working. $\endgroup$ Jan 14, 2018 at 13:29
  • $\begingroup$ Joining line (highlighted by yellow square: updated figure) still present in graph. $\endgroup$ Jan 14, 2018 at 13:37
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    $\begingroup$ @GopalVerma It does work. $\endgroup$
    – corey979
    Jan 14, 2018 at 16:33
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Another alternative is to insert a Null element where you want a break in the line:

data2 = {{0, 0}, {0.5, 2}, {1, 5}, {2, 8.5}, {4, 10}, Null, 
  {0, 0}, {0.5, 4}, {1, 7}, {2, 9.5}, {4, 12}, Null, 
  {0, 0}, {0.5, 5}, {1, 9}, {2, 12}, {4, 18}};
ListLinePlot[data2]

enter image description here

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  • $\begingroup$ (+1). Or alternatively: ListLinePlot[Riffle[data, Null, 6]] $\endgroup$
    – user1066
    Jan 14, 2018 at 19:28

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