mllib

Spark相关知识

旧时模样 提交于 2019-12-05 17:18:24
基本概念: Spark作为新一代大数据计算引擎,因为内存计算的特性,具有比hadoop更快的计算速度。是一个分布式计算框架,旨在简化运行于计算机集群上的并行程序的编写。 RDD:是spark核心数据处理模型,弹性分布式数据集(Resilient Distributed Dataset)是分布式内存的一个抽象概念,提供了一个高度受限的共享内存模型。一个RDD包含多个分区(Partition)。 DAG:有向无环图(Directed Acyclic Graph)反应RDD之间的依赖关系。 Executor:运行在工作节点(WorkNode)的一个进程,负责运行Task。 Application:用户编写的Spark程序。 Task:运行在Executor上的工作单元。 Job:一个Job包含多个RDD及作用于相应RDD上的各种操作。 Stage:是Job的基本调度单位,一个Job会分为多组Task,每组Task被称为Stage,或者也被称为TaskSet,代表了一组由关联的、相互之间没有shuffle依赖关系的任务组成的任务集。 以下是Spark中各种概念之间的相互关系: Spark组件: Spark主要包含了Spark Core、Spark SQL、Spark Streaming、MLLib和GraphX 等组件 。 Spark Core:Spark Core包含Spark的基本功能

Spark MLLib 2.0 Categorical Features in pipeline

匿名 (未验证) 提交于 2019-12-03 08:59:04
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效,请关闭广告屏蔽插件后再试): 问题: I'm trying to build a decision tree based on log files. Some feature sets are large containing thousands of unique values. I'm trying to use the new idioms of pipeline and data frame in Java. I've built a pipeline with several StringIndexer pipeline stages for each of the categorical feature columns. Then I use a VectorAssembler to create a features vector. The resultant data frame looks perfect to me after the VectorAssembler stage. My pipeline looks approximately like StringIndexer-> StringIndexer-> StringIndexer->VectorAssembler-

How to serve a Spark MLlib model?

匿名 (未验证) 提交于 2019-12-03 07:50:05
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效,请关闭广告屏蔽插件后再试): 问题: I'm evaluating tools for production ML based applications and one of our options is Spark MLlib , but I have some questions about how to serve a model once its trained? For example in Azure ML, once trained, the model is exposed as a web service which can be consumed from any application, and it's a similar case with Amazon ML. How do you serve/deploy ML models in Apache Spark ? 回答1: From one hand, a machine learning model built with spark can't be served the way you serve in Azure ML or Amazon ML in a traditional manner. Databricks claims

Spark MLlib LDA, how to infer the topics distribution of a new unseen document?

匿名 (未验证) 提交于 2019-12-03 03:04:01
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效,请关闭广告屏蔽插件后再试): 问题: i am interested in applying LDA topic modelling using Spark MLlib. I have checked the code and the explanations in here but I couldn't find how to use the model then to find the topic distribution in a new unseen document. 回答1: As of Spark 1.5 this functionality has not been implemented for the DistributedLDAModel . What you're going to need to do is convert your model to a LocalLDAModel using the toLocal method and then call the topicDistributions(documents: RDD[(Long, Vector]) method where documents are the new (i.e. out-of-training)

Spark mllib predicting weird number or NaN

匿名 (未验证) 提交于 2019-12-03 03:04:01
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效,请关闭广告屏蔽插件后再试): 问题: I am new to Apache Spark and trying to use the machine learning library to predict some data. My dataset right now is only about 350 points. Here are 7 of those points: "365","4",41401.387,5330569 "364","3",51517.886,5946290 "363","2",55059.838,6097388 "362","1",43780.977,5304694 "361","7",46447.196,5471836 "360","6",50656.121,5849862 "359","5",44494.476,5460289 Here's my code: def parsePoint(line): split = map(sanitize, line.split(',')) rev = split.pop(-2) return LabeledPoint(rev, split) def sanitize(value): return float(value.strip('"'))

PySpark & MLLib: Random Forest Feature Importances

匿名 (未验证) 提交于 2019-12-03 02:05:01
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效,请关闭广告屏蔽插件后再试): 问题: I'm trying to extract the feature importances of a random forest object I have trained using PySpark. However, I do not see an example of doing this anywhere in the documentation, nor is it a method of RandomForestModel. How can I extract feature importances from a RandomForestModel regressor or classifier in PySpark? Here's the sample code provided in the documentation to get us started; however, there is no mention of feature importances in it. from pyspark.mllib.tree import RandomForest from pyspark.mllib.util import MLUtils # Load and

Spark MlLib linear regression (Linear least squares) giving random results

匿名 (未验证) 提交于 2019-12-03 01:23:02
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效,请关闭广告屏蔽插件后再试): 问题: Im new in spark and Machine learning in general. I have followed with success some of the Mllib tutorials, i can't get this one working: i found the sample code here : https://spark.apache.org/docs/latest/mllib-linear-methods.html#linear-least-squares-lasso-and-ridge-regression (section LinearRegressionWithSGD) here is the code: import org.apache.spark.mllib.regression.LabeledPoint import org.apache.spark.mllib.regression.LinearRegressionModel import org.apache.spark.mllib.regression.LinearRegressionWithSGD import org.apache.spark.mllib

Spark MLlib֮FPGrowth

匿名 (未验证) 提交于 2019-12-02 23:40:02
版权声明:转载请说明出处 https://blog.csdn.net/qq_16669583/article/details/91441797 package mllib.associationrule import org.apache.spark.mllib.fpm.{FPGrowth, FPGrowthModel} import org.apache.spark.rdd.RDD import org.apache.spark.{SparkConf, SparkContext} import scala.io.{BufferedSource, Source} /** * created by LMR on 2019/6/11 */ object FPGrowthTest { def main(args: Array[String]): Unit = { val conf: SparkConf = new SparkConf().setMaster("local[*]").setAppName("svm") val sc = new SparkContext(conf) //从windows本地读取数据,转化为RDD[Vector] val source: BufferedSource = Source.fromFile("E:\\IDEAWorkPlace\\SparkTest

Spark大数据处理系列之Machine Learning

匿名 (未验证) 提交于 2019-12-02 23:34:01
Spark的机器学习库(Spark MLlib),包括各种机器学习算法:协同过滤算法、聚类算法、分类算法和其他算法。在前面的《Spark大数据处理》系列文章,介绍Apache Spark框架,介绍如何使用Spark SQL库的SQL接口去访问数据,使用Spark Streaming进行实时流式数据处理和分析。在本篇文章,作者将讨论机器学习概念以及如何使用Spark MLlib来进行预测分析。后面将会使用一个例子展示Spark MLlib在机器学习领域的强悍。Spark机器学习API包含两个package:spark.mllib 和spark.ml。 spark.mllib 包含基于弹性数据集(RDD)的原始Spark机器学习API。它提供的机器学习技术有:相关性、分类和回归、协同过滤、聚类和数据降维。spark.ml提供建立在DataFrame的机器学习API,DataFrame是Spark SQL的核心部分。这个包提供开发和管理机器学习管道的功能,可以用来进行特征提取、转换、选择器和机器学习算法,比如分类和回归和聚类。本篇文章聚焦在Spark MLlib上,并讨论各个机器学习算法。下篇文章将讲述Spark ML以及如何创建和管理数据管道。 机器学习和数据科学 机器学习是从已经存在的数据进行学习来对将来进行数据预测,它是基于输入数据集创建模型做数据驱动决策。数据科学是从海里数据集

掌握Spark机器学习库 大数据开发技能更进一步

匿名 (未验证) 提交于 2019-12-02 23:32:01
掌握Spark机器学习库 大数据开发技能更进一步 “大数据时代”已经不是一个新鲜词汇了,随着技术的商业化推广,越来越多的大数据技术已经进入人们的生活。与此同时,大数据技术的相关岗位需求也越来越多,更多的同学希望向大数据方向转型。本课程主要讲解Spark机器学习库,侧重实践的讲解,同时也以浅显易懂的方式介绍机器学习算法的内在原理。学习本课程,可以为想要转型大数据工程师或是入行大数据工作的同学提供实践指导作用。欢迎感兴趣的小伙伴们一起来学习。 第1章 初识机器学习 在本章中将带领大家概要了解什么是机器学习、机器学习在当前有哪些典型应用、机器学习的核心思想、常用的框架有哪些,该如何进行选型等相关问题。 1-1 导学 试看 1-2 机器学习概述 1-3 机器学习核心思想 1-4 机器学习的框架与选型… 第2章 初识MLlib 本章中,将介绍Spark的机器学习库,对比Spark当前两种机器学习库(MLLib/ML)的区别,同时介绍Spark机器学习库的应用场景以及行业应用优势。 2-1 MLlib概述 2-2 MLlib的数据结构 2-3 MLlib与ml 2-4 MLlib的应用场景 第3章 实战环境搭建 本章中,将介绍如何进行实战环境搭建。包括如何完成Spark环境安装配置、如何通过Spark Shell进行编程,并通过 Wordcount 入门程序,完成部署和测试。 3-1