Error in fit examples of the documentation

[phcournede]

Hi,
I'm discovering this great package. And running the examples given in the notebook of the documentation I face an unexpected error:

the three lines of the notebook (In[17], In[18], In[19]) when running
fit(BayesNet, data, (:a=>:b), [StaticCPD{Normal}, LinearGaussianCPD])
or
fit(BayesNet, data, (:a=>:b), LinearGaussianCPD)
or

data = DataFrame(c=[1,1,1,1,2,2,2,2,3,3,3,3], 
                 b=[1,1,1,2,2,2,2,1,1,2,1,1],
                 a=[1,1,1,2,1,1,2,1,1,2,1,1])

fit(DiscreteBayesNet, data, (:a=>:b, :a=>:c, :b=>:c))

give the same error:

MethodError: Cannot convert an object of type Nothing to an object of type Int64
Closest candidates are:
convert(::Type{T}, !Matched::T) where T<:Number at number.jl:6
convert(::Type{T}, !Matched::Number) where T<:Number at number.jl:7
convert(::Type{T}, !Matched::Ptr) where T<:Integer at pointer.jl:23
...
LightGraphs.SimpleGraphs.SimpleEdge{Int64}(::Nothing, ::Nothing) at simpleedge.jl:7
add_edge!(::LightGraphs.SimpleGraphs.SimpleDiGraph{Int64}, ::Nothing, ::Nothing) at SimpleGraphs.jl:90
_get_dag(::DataFrame, ::Tuple{Pair{Symbol,Symbol}}) at learning.jl:34
fit(::Type{BayesNet}, ::DataFrame, ::Pair{Symbol,Symbol}, ::Array{DataType,1}) at learning.jl:59
top-level scope at BayesNets.jl:44

I am with Windows, Atom, Julia 1.4.2.

Is it only happening for me?
Thanks if you can help.

[phcournede]

OK. I think that I found the problem.
When data is a DataFrame, names(data) returns a list of strings, while for the different functions in learning.jl, we need lists of symbols. Therefore: names(data) should become propertynames(data).
It worked for me with this modification.
I'm however surprised that nobody has encountered the problem before.

If somebody is in charge of the package, maybe it could be worth integrating this little modification.

[mykelk]

Thanks so much! I think this is due to a recent change in DataFrames.jl.

[phcournede]

Thanks to all of you for this great package !