Preview: http://54.82.240.23:4000/mllib-guide.html Table of contents: * Basics * Data types * Summary statistics * Classification and regression * linear support vector machine (SVM) * logistic regression * linear linear squares, Lasso, and ridge regression * decision tree * naive Bayes * Collaborative Filtering * alternating least squares (ALS) * Clustering * k-means * Dimensionality reduction * singular value decomposition (SVD) * principal component analysis (PCA) * Optimization * stochastic gradient descent * limited-memory BFGS (L-BFGS) Author: Xiangrui Meng <meng@databricks.com> Closes #422 from mengxr/mllib-doc and squashes the following commits: 944e3a9 [Xiangrui Meng] merge master f9fda28 [Xiangrui Meng] minor 9474065 [Xiangrui Meng] add alpha to ALS examples 928e630 [Xiangrui Meng] initialization_mode -> initializationMode 5bbff49 [Xiangrui Meng] add imports to labeled point examples c17440d [Xiangrui Meng] fix python nb example 28f40dc [Xiangrui Meng] remove localhost:4000 369a4d3 [Xiangrui Meng] Merge branch 'master' into mllib-doc 7dc95cc [Xiangrui Meng] update linear methods 053ad8a [Xiangrui Meng] add links to go back to the main page abbbf7e [Xiangrui Meng] update ALS argument names 648283e [Xiangrui Meng] level down statistics 14e2287 [Xiangrui Meng] add sample libsvm data and use it in guide 8cd2441 [Xiangrui Meng] minor updates 186ab07 [Xiangrui Meng] update section names 6568d65 [Xiangrui Meng] update toc, level up lr and svm 162ee12 [Xiangrui Meng] rename section names 5c1e1b1 [Xiangrui Meng] minor 8aeaba1 [Xiangrui Meng] wrap long lines 6ce6a6f [Xiangrui Meng] add summary statistics to toc 5760045 [Xiangrui Meng] claim beta cc604bf [Xiangrui Meng] remove classification and regression 92747b3 [Xiangrui Meng] make section titles consistent e605dd6 [Xiangrui Meng] add LIBSVM loader f639674 [Xiangrui Meng] add python section to migration guide c82ffb4 [Xiangrui Meng] clean optimization 31660eb [Xiangrui Meng] update linear algebra and stat 0a40837 [Xiangrui Meng] first pass over linear methods 1fc8271 [Xiangrui Meng] update toc 906ed0a [Xiangrui Meng] add a python example to naive bayes 5f0a700 [Xiangrui Meng] update collaborative filtering 656d416 [Xiangrui Meng] update mllib-clustering 86e143a [Xiangrui Meng] remove data types section from main page 8d1a128 [Xiangrui Meng] move part of linear algebra to data types and add Java/Python examples d1b5cbf [Xiangrui Meng] merge master 72e4804 [Xiangrui Meng] one pass over tree guide 64f8995 [Xiangrui Meng] move decision tree guide to a separate file 9fca001 [Xiangrui Meng] add first version of linear algebra guide 53c9552 [Xiangrui Meng] update dependencies f316ec2 [Xiangrui Meng] add migration guide f399f6c [Xiangrui Meng] move linear-algebra to dimensionality-reduction 182460f [Xiangrui Meng] add guide for naive Bayes 137fd1d [Xiangrui Meng] re-organize toc a61e434 [Xiangrui Meng] update mllib's toc
5.2 KiB
layout | title |
---|---|
global | Machine Learning Library (MLlib) |
MLlib is a Spark implementation of some common machine learning algorithms and utilities, including classification, regression, clustering, collaborative filtering, dimensionality reduction, as well as underlying optimization primitives:
- Basics
- data types
- summary statistics
- Classification and regression
- Collaborative filtering
- alternating least squares (ALS)
- Clustering
- k-means
- Dimensionality reduction
- singular value decomposition (SVD)
- principal component analysis (PCA)
- Optimization
- stochastic gradient descent
- limited-memory BFGS (L-BFGS)
MLlib is currently a beta component under active development. The APIs may change in the future releases, and we will provide migration guide between releases.
Dependencies
MLlib uses linear algebra packages Breeze, which depends on
netlib-java, and
jblas.
netlib-java
and jblas
depend on native Fortran routines.
You need to install the
gfortran runtime library if it is not
already present on your nodes. MLlib will throw a linking error if it cannot detect these libraries
automatically. Due to license issues, we do not include netlib-java
's native libraries in MLlib's
dependency set. If no native library is available at runtime, you will see a warning message. To
use native libraries from netlib-java
, please include artifact
com.github.fommil.netlib:all:1.1.2
as a dependency of your project or build your own (see
instructions).
To use MLlib in Python, you will need NumPy version 1.4 or newer.
Migration guide
From 0.9 to 1.0
In MLlib v1.0, we support both dense and sparse input in a unified way, which introduces a few breaking changes. If your data is sparse, please store it in a sparse format instead of dense to take advantage of sparsity in both storage and computation.
We used to represent a feature vector by Array[Double]
, which is replaced by
Vector
in v1.0. Algorithms that used
to accept RDD[Array[Double]]
now take
RDD[Vector]
. LabeledPoint
is now a wrapper of (Double, Vector)
instead of (Double, Array[Double])
. Converting
Array[Double]
to Vector
is straightforward:
{% highlight scala %} import org.apache.spark.mllib.linalg.{Vector, Vectors}
val array: Array[Double] = ... // a double array val vector: Vector = Vectors.dense(array) // a dense vector {% endhighlight %}
Vectors
provides factory methods to create sparse vectors.
Note. Scala imports scala.collection.immutable.Vector
by default, so you have to import org.apache.spark.mllib.linalg.Vector
explicitly to use MLlib's Vector
.
We used to represent a feature vector by double[]
, which is replaced by
Vector
in v1.0. Algorithms that used
to accept RDD<double[]>
now take
RDD<Vector>
. LabeledPoint
is now a wrapper of (double, Vector)
instead of (double, double[])
. Converting double[]
to
Vector
is straightforward:
{% highlight java %} import org.apache.spark.mllib.linalg.Vector; import org.apache.spark.mllib.linalg.Vectors;
double[] array = ... // a double array Vector vector = Vectors.dense(array) // a dense vector {% endhighlight %}
Vectors
provides factory methods to
create sparse vectors.
We used to represent a labeled feature vector in a NumPy array, where the first entry corresponds to
the label and the rest are features. This representation is replaced by class
LabeledPoint
, which takes both
dense and sparse feature vectors.
{% highlight python %} from pyspark.mllib.linalg import SparseVector from pyspark.mllib.regression import LabeledPoint
Create a labeled point with a positive label and a dense feature vector.
pos = LabeledPoint(1.0, [1.0, 0.0, 3.0])
Create a labeled point with a negative label and a sparse feature vector.
neg = LabeledPoint(0.0, SparseVector(3, [0, 2], [1.0, 3.0])) {% endhighlight %}