_summary': undefined method feature_importance' for nil:NilClass (NoMethodError)

[rmontgomery429]

Given you've installed the prerequisites:

gem install 'eps'
brew install libomp

And a have a file as such:

# test.rb
#!/home/test/.rvm/rubies/ruby-2.6.3/bin/ruby
require 'eps'

data = [
  {bedrooms: 1, bathrooms: 1, price: 100000},
  {bedrooms: 2, bathrooms: 1, price: 125000},
  {bedrooms: 2, bathrooms: 2, price: 135000},
  {bedrooms: 3, bathrooms: 2, price: 162000}
]

model = Eps::Model.new(data, target: :price)

File.write("model.pmml", model.to_pmml)

pmml = File.read("model.pmml")

model = Eps::Model.load_pmml(pmml)

puts model.summary

You will received an error:

Traceback (most recent call last):
        4: from ./test.rb:21:in `<main>'
        3: from /workspace/.rvm/gems/eps-0.3.2/lib/eps/model.rb:60:in `method_missing'
        2: from /workspace/.rvm/gems/eps-0.3.2/lib/eps/model.rb:60:in `public_send'
        1: from /workspace/.rvm/gems/eps-0.3.2/lib/eps/base_estimator.rb:69:in `summary'
/workspace/.rvm/gems/eps-0.3.2/lib/eps/lightgbm.rb:7:in `_summary': undefined method `feature_importance' for nil:NilClass (NoMethodError)

Which is this line:

eps/lib/eps/lightgbm.rb

Line 7 in 0275134

importance = @booster.feature_importance

I assume the instance variable just isn't set at that point so I may just misunderstand how the file is to be used but I would think that I would be able to load the model and use it to get the summary without needing to re-train.

Is that not the case?

[ankane]

Hey @rmontgomery429, nice find. Unfortunately, the summary isn't available for loaded models, as the feature importance isn't stored in the PMML. I added a better error message for this on master.