shuffle

Shuffle all data in datastore

Syntax

dsrand = shuffle(ds)

Description

dsrand = shuffle(ds) returns a datastore object containing a random ordering of the data from ds.

Examples

Shuffle Files

Create an ImageDatastore object imds. Shuffle the files to create a new datastore containing the same files in random order.

imds = imageDatastore(fullfile(matlabroot, 'toolbox', 'matlab', {'demos','imagesci'}),'LabelSource','foldernames','FileExtensions', {'.jpg', '.png', '.tif'})

imds = 

  ImageDatastore with properties:

      Files: {
             ' ...\matlab\toolbox\matlab\demos\cloudCombined.jpg';
             ' ...\matlab\toolbox\matlab\demos\example.tif';
             ' ...\matlab\toolbox\matlab\demos\landOcean.jpg'
              ... and 5 more
             }
     Labels: [demos; demos; demos ... and 5 more categorical]
    ReadFcn: @readDatastoreImage

imdsrand = shuffle(imds)

imdsrand = 

  ImageDatastore with properties:

      Files: {
             ' ...\matlab\toolbox\matlab\demos\street2.jpg';
             ' ...\matlab\toolbox\matlab\demos\landOcean.jpg';
             ' ...\matlab\toolbox\matlab\imagesci\corn.tif'
              ... and 5 more
             }
     Labels: [demos; demos; imagesci ... and 5 more categorical]
    ReadFcn: @readDatastoreImage

Input Arguments

ds — Input datastore

object

Input datastore, specified as a datastore object. The input datastore can be any datastore for which isShuffleable returns true (such as imageDatastore). The input datastore also can be a CombinedDatastore, SequentialDatastore, or TransformedDatastore for which all underlying datastores are shuffleable.

Output Arguments

dsrand — Output datastore

object

Output datastore, returned as a datastore object containing randomly ordered data from ds.

Extended Capabilities

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

Usage notes and limitations:

• In a thread-based environment, you can use shuffle only with the following datastores:

  • ImageDatastore objects

  • CombinedDatastore, SequentialDatastore, or TransformedDatastore objects you create from ImageDatastore objects by using combine or transform

  You can use shuffle with other datastores if you have Parallel Computing Toolbox™. To do so, run the function using a process-backed parallel pool instead of using backgroundPool or ThreadPool (use either ProcessPool or ClusterPool).

For more information, see Run MATLAB Functions in Thread-Based Environment.

Version History

Introduced in R2016a