Possible issue for IsolationForest Division by zero

[indianalalal]

Hello,

I'm trying to use IsolationForest.

$dataset =  new CSV('test.csv', false);
$dataset = Unlabeled::fromIterator($dataset);

$oneHotEncoder = new OneHotEncoder();
$dataset->apply($oneHotEncoder);

$estimator = new IsolationForest(2, 0.1, 0.5); 
$estimator->train($dataset);

There is an exemple of the csv content. In reality I have more than 1000 lines

1,1,46,3,1
1,1,58,6,3
2,5,52,3,1
1,11,52,3,3
2,11,52,6,3
3,1,46,3,1
3,1,58,6,3
3,11,52,3,3

And I have this issue

In IsolationForest.php line 311:
Division by zero  

Is there a problem with the code or with my data?
Thx

[andrewdalpino]

Hey @indianalalal there's no need to one-hot encode your categorical features with IsolationForest since it's compatible with categorical features. The division by zero is because there managed to be a split of samples where all features for the randomly selected continuous column were zero. This could be related to your one-hot encoding.