[SOLVED] Why does Incanter lose column title when only querying one column?

Why does Incanter lose column title when only querying one column?

When selecting two columns from a dataset, the result has the two given column titles as expected. But when only specifying one column, the one resulting column loses it's title, instead, it is titled "0":

This makes it hard to use $order or whatever in later steps that take column names.

That is, this will work

(with-data data   
  (->> ($ [:foo :bar])
       ($order [:foo] :asc)
       (view)))

and this will fail

(with-data data
  (->> ($ [:foo])
       ($order [:foo] :asc)
       (view)))

Any ideas what is going wrong or what to do?

Solution

which version of Incanter are you using? This behavior was changed in recent versions, and at least 1.5.4 works correctly. But take into account that behavior of $ is different when you pass the column name as single element, and as vector:

incanter.main=> (def data (dataset [:foo :bar] [[:a :b] [:c :d]]))
#'incanter.main/data
incanter.main=> ($ :foo data)
(:a :c)
incanter.main=> ($ [:foo] data)

| :foo |
|------|
|   :a |
|   :c |