This course focuses onSpark, the hottest, most popular and promising technology in the big Data world today. In this course, from shallow to deep, based on a large number of case studies, in-depth analysis and explanation of Spark, and will contain completely from the enterprise real complex business needs to extract the actual case. The course will cover Scala programming,
crossvalidator is very high, however, compared with heuristic manual validation, cross-validation is still a very useful parameter selection method in existence.
Scala:
Import org.apache.spark.ml.Pipeline Import org.apache.spark.ml.classification.LogisticRegression Import Org.apache.spark.ml.evaluation.BinaryClassificationEvaluator import org.apache.spark.ml.feature. {HASHINGTF, tokenizer} import org.apache.spark.ml.linalg.Vector import org.apache.s
3, hands-on generics in Scalageneric generic classes and generic methods, that is, when we instantiate a class or invoke a method, you can specify its type, because Scala generics and Java generics are consistent and are not mentioned here. 4, hands on. Implicit conversions, implicit parameters, implicit classes in Scalaimplicit conversion is one of the key points that many people learn about Scala, which i
3, hands on the abstract class in ScalaThe definition of an abstract class requires the use of the abstract keyword:
The above code defines and implements the abstract method, it is important to note that we put the direct running code in the trait subclass of the app, about the inside of the app helps us implement the Main method and manages the code written by the engineer;Here's a look at the use of uninitialized variables in an abstract class:
4, hands-on trait in ScalaTrait
none, and below we look at the use of option:
Next, take a look at filter processing:
Here's a look at the zip operation for the collection:
Here's a look at the partition of the collection:
We can use flatten's multi-collection for flattening operations:
Flatmap is a combination of map and flatten operations, first map operation and then flatten operation:
"Spark Asia-Pacific Research ser
copied this Scala version.
Sparkwordcount.scala class implements the spark Chinese word segmentation statistics core function, is in the DT Big Data dream Factory Wang Jialin Teacher's sparkwordcount code based on rewrite.
First, the main functional steps are moved from the companion object's main method to the Sparkwordcount class, and split into multiple methods so that the main method of the companion o
The spark kernel is developed by the Scala language, so it is natural to develop spark applications using Scala. If you are unfamiliar with the Scala language, you can read Web tutorials A Scala Tutorial for Java programmers or re
The Java version of the spark Big Data Chinese word Segmentation Statistics program was completed, and after a week of effort, the Scala version of the sparkBig Data Chinese Word segmentation Statistics program also made out, here to share to you want to learn spark friends.The following is the final interface of the program, and the Java version is not very diff
2.10, because I am through spark-core_${scala.version} is looking for spark dependency package, Some days ago a colleague followed this to build, because the version of the last spark dependent package always fail. Please check your version yourself.
Here are a few small questions to keep in mind:There's going to be Src/main/
This article first describes how to configure the Maven+scala development environment in Eclipse, and then describes how to implement the spark local run. Finally, the spark program written by Scala is successfully run.
At first, my Eclipse+maven environment was well configured.
System: Win7
Eclipse version: Luna rele
1. PreparationThis article focuses on how to build the Spark 2.11 stand-alone development environment in Ubuntu 16.04, which is divided into 3 parts: JDK installation, Scala installation, and spark installation.
JDK 1.8:jdk-8u171-linux-x64.tar.gz
Scala 11.12:scala
2, Scala simple example
Reference Tutorial: HTTPS://YQ.ALIYUN.COM/TOPIC/69 2.1 Interactive Programming
Spark-shell is spark interactive operating mode, provides interactive programming, side-knocking code side execution, do not need to create program source files, convenient debugging procedures, conducive to rapid le
, implicit and implicit images, and implicit conversions are features of Scala. Scala language because there is an implicit conversion so there is a mistake before you will be able to judge the implicit in the same meaning can be out of the function of the Imperial Army, if any, it will adjust the implicit conversion method to complete this conversion. The Scala
3, hands-on generics in Scala generic generic classes and generic methods, that is, when we instantiate a class or invoke a method, you can specify its type, because Scala generics and Java generics are consistent and are not mentioned here. 4, hands on. Implicit conversions, implicit parameters, implicit classes in Scala Implicit conversion is one of the ke
Learn Spark 2.0 (new features, real projects, pure Scala language development, CDH5.7)Share the network disk download--https://pan.baidu.com/s/1c2f9zo0 password: pzx9Spark entered the 2.0 era, introducing many excellent features, improved performance, and more user-friendly APIs. In the "unified programming" is very impressive, the implementation of offline computing and Flow computing API unification, the
Scala Beginner's intermediate-Advanced Classic (66th: Scala concurrent programming experience and its application in Spark source code) content introduction and video link2015-07-24DT Big Data Dream FactoryFrom tomorrow onwards, be a diligent person.Watch videos, videos, share videosDT Big Data Dream Factory-scala--Adv
Directory installation JDK installation Scala IDE for Eclipse configuration spark configuration Hadoop create Maven engineering Scala code entry 7 Item 8 Item 9
Installing the JDK
Requires installation of jdk1.8 or later.Back to Catalog
installing Scala IDE for Eclipse
] = spark.MappedRDD@2ee9b6e32. RDD has two types of operations: action (return values) and transformations (return a new RDD). Below we start a few actions:
Scala> textFile. count () // Number of items in this RDDres0: Long = 74 scala> textFile. first () // First item in this RDDres1: String = # Spark3. Use the filter in transformations to return the new RDD of a file subset.
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