h2o implementation in R

Question

I am learning h2o package now,

1. I installed h2o package from CRAN and couln't run this code

   ## To import small iris data file from H\ :sub:`2`\ O's package
   irisPath = system.file("extdata", "iris.csv", package="h2o")
   iris.hex = h2o.importFile(localH2O, path = irisPath, key = "iris.hex")
   

I am getting the below error,

Error in h2o.importFile(localH2O, path = irisPath, key = "iris.hex") : unused argument (key = "iris.hex")

2. My second question is, Do we have good resources to learn h2o in R apart from this:

http://h2o-release.s3.amazonaws.com/h2o/rel-lambert/5/docs-website/Ruser/rtutorial.html

3. My third question is I want to know how the h2o works in simple words.?

Answer 1

The reason this code no longer works is that there was a breaking API change from H2O 2.0 to H2O 3.0 back in 2015. The docs you have discovered (probably via a Google search) are for a very old version of H2O 2.0. The up-to-date docs can always be found at http://docs.h2o.ai/h2o/latest-stable/h2o-docs/index.html

Answer 2

Answering your error question:

H2O changed a bit from this documentation. Reading the iris file works as follows:

iris.hex = h2o.importFile(path = irisPath, destination_frame = "iris.hex")

Your second (and third question) is against SO rules. But below you will find a short list of resources:

1. H2O training materials (go to the h2o.ai website) and go to general documentation. You can find all the material there presented on h2o world 2015. There is also a link to h2o university.
2. Check their blog. There are some gold nuggets in there.
3. Read the booklets they have available on GBM, GLM, Deep Learning. They contain examples in R and Python.
4. Kaggle. Search the scripts / kernels for h2o.

As for your third question, read their "Why H2O pages".