flatMap

R2026b

Class: matlab.compiler.mlspark.RDD
Namespace: matlab.compiler.mlspark

(To be removed) Return a new RDD by first applying a function to all elements of an existing RDD, and then flattening the results

matlab.compiler.mlspark.RDD.flatMap will be removed in a future release. There is no replacement functionality. For more information, see Version History.

Syntax

result = flatMap(obj,func,varargin)


Description

result = flatMap(obj,func,varargin) returns a new RDD result by first applying a function func to all elements of obj, and then flattening the results.

Input Arguments

obj — Input RDD

RDD object

An input RDD on which a function is applied, specified as a RDD object.

func — Function to apply to each element

function handle

Function to be applied to each element in the input RDD, specified as a function handle.

Example:

Data Types: function_handle

varargin — Variable-length input argument list

valid inputs to the transformation function

A variable-length input argument list representing inputs to the function that is being applied.

Output Arguments

result — Output RDD

RDD object

An output RDD, returned as a RDD object.

Examples

Apply a Function to an RDD and Flatten the Results

%% Connect to Spark
sparkProp = containers.Map({'spark.executor.cores'}, {'1'});
conf = matlab.compiler.mlspark.SparkConf('AppName','myApp', ...
                        'Master','local[1]','SparkProperties',sparkProp);
sc = matlab.compiler.mlspark.SparkContext(conf);

%% flatMap
inRDD = sc.parallelize({'A','B'});
flatRDD = inRDD.flatMap(@(x)({x,1}));
viewRes = flatRDD.collect()

Version History

Introduced in R2016b

R2026b: To be removed

Support for deploying applications using the MATLAB API for Spark™ will be removed in a future release. There is no replacement functionality.