addMembers

Add members to labeled signal set

Syntax

addMembers(lss,src)

addMembers(lss,src,tinfo)

addMembers(lss,src,tinfo,mnames)

Description

addMembers(lss,src) adds members to the labeled signal set lss from the input data source src.

addMembers(lss,src,tinfo) sets the time information for the new members to tinfo.

addMembers(lss,src,tinfo,mnames) sets the names of the new members to mnames. The length of mnames must be equal to the number of new members.

Examples

Add Member to Labeled Signal Set

Load a labeled signal set containing recordings of whale songs.

load whales
lss

lss = 
  labeledSignalSet with properties:

             Source: {2x1 cell}
         NumMembers: 2
    TimeInformation: "sampleRate"
         SampleRate: 4000
             Labels: [2x3 table]
        Description: "Characterize wave song regions"

 Use labelDefinitionsHierarchy to see a list of labels and sublabels.
 Use setLabelValue to add data to the set.

Retrieve the second member of the set and plot it.

[song,tinfo] = getSignal(lss,2);

t = (0:length(song)-1)/tinfo.SampleRate;

plot(t,song)

Remove the first and last seconds of the retrieved signal.

song2 = song(t>1 & t<t(end)-1);
t2 = (0:length(song2)-1)/tinfo.SampleRate;

plot(t2,song2)

Add the shorter signal as a new member of the labeled set.

addMembers(lss,song2)
lss

lss = 
  labeledSignalSet with properties:

             Source: {3x1 cell}
         NumMembers: 3
    TimeInformation: "sampleRate"
         SampleRate: 4000
             Labels: [3x3 table]
        Description: "Characterize wave song regions"

 Use labelDefinitionsHierarchy to see a list of labels and sublabels.
 Use setLabelValue to add data to the set.

Flip the shorter signal upside-down and add it as a new member of the labeled set. Specify that the new member is sampled at 1 kHz.

addMembers(lss,flipud(song2),1000)
lss.SampleRate

ans = 4×1

        4000
        4000
        4000
        1000

Input Arguments

lss — Labeled signal set

labeledSignalSet object

Labeled signal set, specified as a labeledSignalSet object.

Example: labeledSignalSet({randn(100,1) randn(10,1)},signalLabelDefinition('female')) specifies a two-member set of random signals containing the attribute 'female'.

src — Input data source

matrix | cell array | timetable | signalDatastore object | audioDatastore object

Input data source, specified as a matrix, a cell array, a timetable, a signalDatastore object, or an audioDatastore (Audio Toolbox) object. The particular form of src depends on the Source property of lss.

• If Source is a cell array of matrices:

  • Specify src as a matrix to add one member to the set.

  • Specify src as a cell array of matrices to add multiple members to the set.

• If Source is a cell array containing cell arrays of vectors:

  • Specify src as a cell array of vectors to add one member to the set.

  • Specify src as a cell array containing cell arrays of vectors to add multiple members to the set.

• If Source is a cell array of timetables:

  • Specify src as a timetable to add one member to the set.

  • Specify src as a cell array of timetables to add multiple members to the set.

• If Source is a datastore, then add members by setting src as another datastore that points to new files.

Example: {randn(10,3),randn(17,9)} specifies two members. The first member contains three 10-sample signals. The second member contains nine 17-sample signals.

Example: {{randn(10,1)},{randn(17,1),randn(27,1)}} specifies two members. The first member contains one 10-sample signal. The second member contains a 17-sample signal and a 27-sample signal.

Example: {{timetable(seconds(1:10)',randn(10,3)),timetable(seconds(1:7)',randn(7,2))},{timetable(seconds(1:3)',randn(3,1))}} specifies two members. The first member contains three signals sampled at 1 Hz for 10 seconds and two signals sampled at 1 Hz for 7 seconds. The second member contains one signal sampled at 1 Hz for 3 seconds.

Example: signalDatastore Object Pointing to Files

Specify the path to a set of sample sound signals included as MAT files with MATLAB®. Each file contains a signal variable and a sample rate. List the names of the files.

folder = fullfile(matlabroot,"toolbox","matlab","audiovideo");
lst = dir(append(folder,"/*.mat"));
nms = {lst(:).name}'

nms = 7x1 cell
    {'chirp.mat'   }
    {'gong.mat'    }
    {'handel.mat'  }
    {'laughter.mat'}
    {'mtlb.mat'    }
    {'splat.mat'   }
    {'train.mat'   }

Create a signal datastore that points to the specified folder. Set the sample rate variable name to Fs, which is common to all files. Generate a subset of the datastore that excludes the file mtlb.mat, which differs from the other files in that the signal variable is not called y.

sds = signalDatastore(folder,"SampleRateVariableName","Fs");
sdss = subset(sds,~strcmp(nms,"mtlb.mat"));

Use the subset datastore as the source for a labeledSignalSet object.

lss = labeledSignalSet(sdss)

lss = 
  labeledSignalSet with properties:

             Source: [1x1 signalDatastore]
         NumMembers: 6
    TimeInformation: "inherent"
             Labels: [6x0 table]
        Description: ""

 Use labelDefinitionsHierarchy to see a list of labels and sublabels.
 Use setLabelValue to add data to the set.

tinfo — Time information for new members

scalar | vector | matrix | duration scalar | duration vector

Time information for new members, specified as a scalar, a vector, a matrix, a duration scalar, or a duration vector. This argument is valid only if the TimeInformation property of lss is 'sampleRate', 'sampleTime', or 'timeValues'.

• If TimeInformation is 'sampleRate', then tinfo specifies sample rate values.

• If TimeInformation is 'sampleTime', then tinfo specifies sample time values.

• If TimeInformation is 'timeValues', then tinfo specifies time values.

If you add multiple members to a set, then specifying only one value of tinfo sets the same value for all members. If you want to specify a different value for each new member, then set tinfo to have multiple values.

When no source has been specified, or when the labeled signal set source is empty, you can change the TimeInformation property to 'sampleRate', 'sampleTime', or 'timeValues' to make lss interpret tinfo correctly.

Example: addMembers(ks,{randn(10,5),randn(10,3)},seconds([1 2])) adds two new members with different time information to ks = labeledSignalSet(randn(10,3),'SampleTime',seconds(1)).

Example: addMembers(ks,{randn(10,5),randn(10,3)},[1:10;2:2:20]') adds two new members with different time information to ks = labeledSignalSet(randn(10,3),'TimeValues',1:10).

mnames — Member names

character vector | string scalar | cell array of character vectors | string array

Member names, specified as a character vector, a string scalar, a cell array of character vectors, or a string array.

Example: labeledSignalSet({randn(100,1) randn(10,1)},'MemberNames',{'llama' 'alpaca'}) specifies a set of random signals with two members, 'llama' and 'alpaca'.

Version History

Introduced in R2018b