Mahout介绍

3.11简介

Mahout:是一个Apache的一个开源的机器学习库，主要实现了三大类算法Recommender

(collaborative filtering)、Clustering、classification。可扩展，用Java实现，用MapReduce实现了部分数据挖掘算法，解决了并行挖掘的问题。

Mahout为数据分析人员，解决了大数据的门槛；为算法工程师提供了基础算法库；为Hadoop开发人员提供了数据建模的标准。

——张丹(Conan)  http://blog.fens.me/hadoop-mahout-roadmap/

3.12Mahout历史演变

Mahout began life in 2008 as a project of Apache`s lucene project .Lucene provides advanced implementations of search ,text mining and information-retrival techniques.In the universe of computer science ,there concepts are adjacent to machine learning  techniques like clustering and to an extent ,classification .As a result,some of the work of the Lucene committers that fell more into these machine learning areas was spun off into its own subproject. Soon after ,Mahout absorbed the Taste open source collaborative filtering project.As of April 2010 ,Mahout became a top-level Apache project in its own right, and get a bran-new elephant rider logo to boot.

——Mahout in Action

25 April 2014 - Goodbye MapReduce

The Mahout community decided to move its codebase onto modern data processing systems that offer a richer programming model and more efficient execution than Hadoop MapReduce. Mahout will therefore reject new MapReduce algorithm implementations from now on. We will however keep our widely used MapReduce algorithms in the codebase and maintain them.

We are building our future implementations on top of a DSL for linear algebraic operations which has been developed over the last months. Programs written in this DSL are automatically optimized and executed in parallel on Apache Spark.

——http://mahout.apache.org/

3.13Hadoop家族中Mahout的结构图

 

主要算法：

算法类	算法名	中文名
分类算法	Logistic Regression	逻辑回归
	Bayesian	贝叶斯
	SVM	支持向量机
	Perceptron	感知器算法
	Neural Network	神经网络
	Random Forests	随机森林
	Restricted Boltzmann Machines	有限波尔兹曼机
聚类算法	Canopy Clustering	Canopy聚类
	K-means Clustering	K均值算法
	Fuzzy K-means	模糊K均值
	Expectation Maximization	EM聚类（期望最大化聚类）
	Mean Shift Clustering	均值漂移聚类
	Hierarchical Clustering	层次聚类
	Dirichlet Process Clustering	狄里克雷过程聚类
	Latent Dirichlet Allocation	LDA聚类
	Spectral Clustering	谱聚类
关联规则挖掘	Parallel FP Growth Algorithm	并行FP Growth算法
回归	Locally Weighted Linear Regression	局部加权线性回归
降维/维约简	Singular Value Decomposition	奇异值分解
	Principal Components Analysis	主成分分析
	Independent Component Analysis	独立成分分析
	Gaussian Discriminative Analysis	高斯判别分析
进化算法	并行化了Watchmaker框架
推荐/协同过滤	Non-distributed recommenders	Taste(UserCF, ItemCF, SlopeOne）
	Distributed Recommenders	ItemCF
向量相似度计算	RowSimilarityJob	计算列间相似度
	VectorDistanceJob	计算向量间距离
非Map-Reduce算法	Hidden Markov Models	隐马尔科夫模型
集合方法扩展	Collections	扩展了java的Collections类

——http://blog.csdn.net

3.14Mahout在Hadoop 平台上的安装

1.下载mahout:http://archive.apache.org/dist/mahout/

2.下载Maven 一般ubuntu系统直接 sudo apt-get install maven

3.将mahout 的文件解压成文件夹mahout 并放入/usr文件夹

sudo tar -zxvf  mahout-distribution-0.9.tar.gz

sudo mv   mahout-distribution-0.9  /usr/mahout

4.创建一个脚本，配置mahout的环境。脚本内容

export JAVA_HOME=/usr/lib/jvm/jdk8/

export MAHOUT_HOME=/usr/mahout9

export MAHOUT_CONF_DIR=/usr/mahout9/conf

export PATH=$MAHOUT_HOME/bin:$MAHOUT_HOME/conf:$PATH

export HADOOP_HOME=/usr/hadoop

export HADOOP_CONF_DIR=/usr/hadoop/conf

export PATH=$PATH:$HADOOP_HOME/bin

5.运行脚本文件，运行mahout命令

6.到这里就表示安装成功，下面下载一个测书数据，是一下mahout 的Kmeans聚类方法。

Sudo wget http://archive.ics.uci.edu/ml/databases/synthetic_control/synthetic_control.data

7.将数据上传到HDFS 上

hdfs fs -mkdir testdata

hdfs fs -put /usr/synthetic_control.data  ./testdata

8.运行k-means聚类算法

mahout -core org.apache.clustering.syntheticcontrol.kmeans.Job