The Signal Labeler app works with real-valued vectors, matrices, MATLAB® timetables, and
objects in the MATLAB Workspace.
Signal Labeler does not support complex-valued signals, signals with
NaN values, multidimensional arrays, or
The signals you import into Signal Labeler can be labeled in samples or in time. This specification stays fixed to ensure consistent labeling. You cannot mix signals in samples and signals with time information in the same session.
Example: Numeric Arrays
num = cos(pi./[4;2]*(0:159))'+randn(160,2);
Example: MATLAB Timetables
tt1 = timetable(num,'SampleRate',100); tt2 = timetable(seconds((0:159)'/100),num);
lss = labeledSignalSet(num);
labeledSignalSet Objects with Time
lst1 = labeledSignalSet(num,'SampleRate',100); lst2 = labeledSignalSet(timetable(seconds((0:159)'/100),num));
To import signals to Signal Labeler from the MATLAB workspace, on the Labeler tab, click
Import ▼ and select
Workspace. In the dialog box, select the signals you want to import.
When specifying the time information for a set of signals that do not have it, select a time specification option in the Import Members From Workspace dialog box.
|Time Specification Option||Description|
|This option enables you to explore and label signals without the need to specify a sample rate or a sample time. It is equivalent to plotting the signal in MATLAB without x-axis information.|
|Use this option when you know the rate at which the signal has been sampled. The sample rate can be expressed in Hz, kHz, MHz, or GHz. To specify the sample rate, you can use a numeric value, the name of a scalar variable in the MATLAB Workspace, or any valid MATLAB expression. Set the sample rate so that the members are plotted in units of time.|
|Use this option when you know the time interval between samples. The sample time can be expressed in seconds, years, days, hours, minutes, milliseconds, microseconds, or nanoseconds. To specify the sample time, you can use a numeric value, the name of a scalar variable in the MATLAB Workspace, or any valid MATLAB expression. Set the sample time so that the members are plotted in units of time.|
Use this option when you know the time value corresponding to each
sample. Specify the time values using a valid MATLAB expression or the name of a variable in the MATLAB workspace. The time values can be stored in a numeric or
In all cases, the app derives a sample rate from the time values and displays it in the Time column of the Labeled Signal Set browser. An asterisk preceding the sample rate indicates that the members are nonuniformly sampled.
Once a signal or set of signals has been imported into Signal Labeler, the chosen time specification stays fixed throughout the labeling session.
If you initially imported a numeric array and specified it in samples, or if you
initially imported a
labeledSignalSet object in samples, you can
subsequently choose only signals in samples. If you choose a numeric array,
Signal Labeler imports it and treats it in samples.
If you initially imported a numeric array and specified its time information, or
if you initially imported a MATLAB timetable or a
labeledSignalSet object with time
information, you can subsequently choose only signals with time information. If you
choose a numeric array, you must set its time information when importing it.
You cannot modify the time information of a
from within Signal Labeler. If the labeled signal set has no time
information, the app treats its members as being in samples. If the labeled signal set
has time information, the app incorporates this information when it imports the signals.
For more information, see the
To be imported successfully, labeled signal sets must obey these additional rules:
If the selection includes two or more labeled signal sets, the labeled signal sets must have unique signal label definitions. If two or more sets share a label definition, the definition must have the same type and data type for all sets.
If the selection includes two or more labeled signal sets, the labeled signal sets
must have unique member names. You cannot change member names from within Signal
Labeler. To change the name of a member of a labeled signal set, use
setMemberNames at the command line.
If you select two or more
labeledSignalSet objects for labeling,
Signal Labeler merges them and creates a single labeled signal set
containing all the members and label values of the input sets. This action is
equivalent to using
the command line.