ClassCastException while using :group-by option for scatter-plot in Incanter

Question

I'm using Incanter 1.9 and I can't get :group-by option in scatter-plot function to work. The statement I am currently trying is:

 (view (scatter-plot :Sepal.Length :Sepal.Width :group-by :Species :data (get-dataset :iris)))  

It produces this error:

 ClassCastException java.lang.String cannot be cast to java.lang.Number clojure.lang.RT.doubleCast (RT.java:1222)  

What am I doing wrong? Is this the correct usage of :group-by in scatter-plot?

Answer 1

This is the correct usage of :group-by. What you test exactly comes from scatter-plot documentation. The example works fine with release 1.5.6 (master).

The release 1.9 is still under development. I did some digging and there had been changes on the way datasets are built and there are some impacts in scatter-plot.

The best is maybe to work with the release 1.5.6.