Still learning the new DataSet feature, I would like to create a ListPlot where the color of the points is to be determined by a column in the dataset. Here is what I have:

(* import and set column names *)
iris = SemanticImport["http://aima.cs.berkeley.edu/data/iris.csv"];
iris = iris[All, <|
    "SepalLength" -> 1, "SepalWidth" -> 2, 
    "PetalLength" -> 3, "PetalWidth" -> 4, "Species" -> 5

(* ListPlot *)
iris[ListPlot, {"PetalLength", "SepalWidth"}]

Now I have no idea how to set the color according the "Species" column. The documentation did not help. Ideally, the plot has a legend mapping colors to species.

Any hint appreciated!


3 Answers 3

color[s_] := Switch[s, "setosa", Red, "versicolor", Green, "virginica", Blue];
              BaseStyle->{PointSize[.015] ,FontSize->16},
              PlotLabel->"Iris Data"]&, 
 {"PetalLength", "SepalWidth","Species"}]

enter image description here

  • $\begingroup$ Great solution! $\endgroup$
    – Karsten W.
    Oct 23, 2014 at 13:51
  • $\begingroup$ @KarstenW., thank you for the Accept. $\endgroup$
    – kglr
    Oct 23, 2014 at 13:57
  • $\begingroup$ Great code. I am using a lot and would like to add a tooltip for each point which displays the values {x,y} but does not succeed to. Thanks for your help. $\endgroup$
    – Porty
    Oct 13, 2017 at 5:54
  • $\begingroup$ @Porty thank you for kind words. I am not able to test but doesn't iris[ListPlot[Style[Tooltip[{#, #2}], color @ #3]&@@@# , ... ] work? $\endgroup$
    – kglr
    Oct 13, 2017 at 6:54
ListPlot[iris[GroupBy[Key["Species"]],All,{"PetalLength", "SepalWidth"}],
   PlotLegends -> "Expressions" ]

enter image description here


Ok, I found a solution to my question.

color[s_] := Switch[s, "setosa", Red, "versicolor", Green, "virginica", Blue];
    List /@ Normal@iris[All, {"SepalLength", "PetalWidth"}],
    PlotStyle -> Normal@(color /@ iris[All, "Species"]),
    PlotLegends -> SwatchLegend @@ 
          Transpose[({color[#], #} & /@ iris[Union, "Species"])]

However, if you have a more Queryish answer, I will upvote and accept yours...


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