# show grouped code output instead of single lines knitr::opts_chunk$set(collapse = TRUE)
This document provides an in-depth introduction to Machine Learning in R: mlr, a framework for machine learning experiments in R.
In this tutorial, we focus on basic functions and applications. More detailed technical information can be found in the manual pages{target="_blank"} which are regularly updated and reflect the documentation of the current package development version.
The tutorial aims to walkthrough basic data analysis tasks step by step. We will use simple examples from classification, regression, cluster and survival analysis to illustrate the main features of the package.
Enjoy reading!
Here we show the mlr
workflow to train, make predictions, and evaluate a learner on a classification problem.
We walk through 5 basic steps that work on any learning problem or method supported by mlr
.
library(mlr) data(iris) # 1) Define the task # Specify the type of analysis (e.g. classification) and provide data and response variable task = makeClassifTask(data = iris, target = "Species") # 2) Define the learner # Choose a specific algorithm (e.g. linear discriminant analysis) lrn = makeLearner("classif.lda") n = nrow(iris) train.set = sample(n, size = 2 / 3 * n) test.set = setdiff(1:n, train.set) # 3) Fit the model # Train the learner on the task using a random subset of the data as training set model = train(lrn, task, subset = train.set) # 4) Make predictions # Predict values of the response variable for new observations by the trained model # using the other part of the data as test set pred = predict(model, task = task, subset = test.set) # 5) Evaluate the learner # Calculate the mean misclassification error and accuracy performance(pred, measures = list(mmce, acc))
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.