readall

Read all signals from datastore

Syntax

data = readall(sds)

data = readall(sds,UseParallel=tf)

Description

data = readall(sds) reads all signal data from the datastore sds.

data = readall(sds,UseParallel=tf) enables you to read data in parallel by setting UseParallel=true. (since R2026a)

To set UseParallel=true, you must have a Parallel Computing Toolbox™ license and specify a signalDatastore object, sds, that contains file data.

Examples

Read and Analyze All Signals in Signal Datastore

Specify the path to four signals included with MATLAB®. The signals are recordings of a bird chirp, a gong, a train, and a splat. All signals are sampled at 8192 Hz.

folder = fullfile(matlabroot,'toolbox','matlab','audiovideo', ...
         ["chirp.mat","gong.mat","train.mat","splat.mat"]);
fs = 8192;
sds = signalDatastore(folder,'SampleRate',fs);

Read the data in the first variables of all the files in the datastore and plot the Fourier synchrosqueezed transform of each signal.

data = readall(sds);

tiledlayout('flow')
for i = 1:length(data)
    nexttile
    fsst(data{i},fs,'yaxis')
end

Input Arguments

sds — Signal datastore

signalDatastore object

Signal datastore, specified as a signalDatastore object.

tf — Option to read data in parallel

false or 0 (default) | true or 1

Since R2026a

Option to read data in parallel, specified as either false or true.

• By default, readall does read data in parallel.

• If you set tf to true, then readall reads data using a parallel pool of workers only if:

  • You have installed Parallel Computing Toolbox.

  • You have enabled automatic pool creation in parallel settings or an open parallel pool exists. For more information on how to control your parallel settings, see Specify Your Parallel Settings (Parallel Computing Toolbox).

  • You have specified a signalDatastore object src that contains file data.

  Otherwise, readall errors out.

Data Types: logical

Output Arguments

data — All signals in signal datastore

cell array

All signals in the signal datastore, returned as a cell array. Each cell of data contains signals from a file or a member. Use the ReadOutputOrientation property of the datastore to control the orientation of data as either a column array or a row array.

Tips

When reading file data, because this function reads all the data in the files at once, you may run out of memory if your dataset is large.

Version History

Introduced in R2020a

R2026a: Read data in parallel

The UseParallel name-value argument in the readall function enables you to read data in parallel. You must have a Parallel Computing Toolbox license to use this functionality.