array2timetable

Convert homogeneous array to timetable

Syntax

TT = array2timetable(X,'RowTimes',rowTimes)

TT = array2timetable(X,'SampleRate',Fs)

TT = array2timetable(X,'TimeStep',dt)

TT = array2timetable(___,'StartTime',t0)

TT = array2timetable(___,'VariableNames',varNames)

Description

TT = array2timetable(X,'RowTimes',rowTimes) converts X and rowTimes to a timetable. X is an M-by-N array and rowTimes is an M-by-1 vector of datetime or duration values. Each column of X becomes a variable of TT. The time values in rowTimes label the rows of the timetable. TT is an M-by-N timetable.

For more information on creating and using timetables, see Timetables.

TT = array2timetable(X,'SampleRate',Fs) uses the sample rate Fs to calculate regularly spaced row times. Fs is a positive numeric scalar that specifies the number of samples per second (Hz). The first row time is zero seconds.

TT = array2timetable(X,'TimeStep',dt) uses the time step dt to calculate regularly spaced row times. dt is a duration or calendar duration value that specifies the length of time between consecutive row times. The first row time is zero seconds.

TT = array2timetable(___,'StartTime',t0) specifies start time t0, instead of zero seconds, as the first row time. You can use this syntax when you create a regular timetable using either the 'SampleRate' or 'TimeStep' name-value pair arguments from either of the previous two syntaxes.

TT = array2timetable(___,'VariableNames',varNames) specifies the names of the variables in the output timetable. You can use this syntax with any of the input arguments of the previous syntaxes.

Examples

Convert Array to Timetable

Convert an array to a timetable. Add a vector of durations as the row times.

X = rand(5,3);
Time = seconds(1:5);
TT = array2timetable(X,'RowTimes',Time)

TT=5×3 timetable
    Time       X1         X2         X3   
    _____    _______    _______    _______

    1 sec    0.81472    0.09754    0.15761
    2 sec    0.90579     0.2785    0.97059
    3 sec    0.12699    0.54688    0.95717
    4 sec    0.91338    0.95751    0.48538
    5 sec    0.63236    0.96489    0.80028

Return the size of the timetable. TT contains five rows and three variables. The set of row times is a table property. The row times are not contained in a table variable.

size(TT)

ans = 1×2

     5     3

Specify Sample Rate

Specify a sample rate of 500 Hz, and convert an array to a timetable.

X = rand(5,3);
TT = array2timetable(X,'SampleRate',500)

TT=5×3 timetable
      Time         X1         X2         X3   
    _________    _______    _______    _______

    0 sec        0.81472    0.09754    0.15761
    0.002 sec    0.90579     0.2785    0.97059
    0.004 sec    0.12699    0.54688    0.95717
    0.006 sec    0.91338    0.95751    0.48538
    0.008 sec    0.63236    0.96489    0.80028

Specify Time Step

Specify a time step of 0.5 seconds, and convert an array to a timetable.

X = rand(5,3);
TT = array2timetable(X,'TimeStep',seconds(0.5))

TT=5×3 timetable
     Time        X1         X2         X3   
    _______    _______    _______    _______

    0 sec      0.81472    0.09754    0.15761
    0.5 sec    0.90579     0.2785    0.97059
    1 sec      0.12699    0.54688    0.95717
    1.5 sec    0.91338    0.95751    0.48538
    2 sec      0.63236    0.96489    0.80028

Specify Start Time

Specify a time step of 15 seconds, and a start time of 5 minutes.

X = rand(5,3);
TT = array2timetable(X,'TimeStep',seconds(15),'StartTime',minutes(5))

TT=5×3 timetable
      Time        X1         X2         X3   
    ________    _______    _______    _______

    5 min       0.81472    0.09754    0.15761
    5.25 min    0.90579     0.2785    0.97059
    5.5 min     0.12699    0.54688    0.95717
    5.75 min    0.91338    0.95751    0.48538
    6 min       0.63236    0.96489    0.80028

Specify Variable Names

Convert an array to a timetable. Specify the row times as a datetime vector. Specify names for the timetable variables.

X = randi([70 90],5,3);
Time = datetime(2016,7,1:5);
varNames = {'Temp1','Temp2','Temp3'};
TT = array2timetable(X,'RowTimes',Time,'VariableNames',varNames)

TT=5×3 timetable
       Time        Temp1    Temp2    Temp3
    ___________    _____    _____    _____

    01-Jul-2016     87       72       73  
    02-Jul-2016     89       75       90  
    03-Jul-2016     72       81       90  
    04-Jul-2016     89       90       80  
    05-Jul-2016     83       90       86  

Input Arguments

X — Input matrix

matrix

Input matrix.

Data Types: double | single | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | string | categorical | datetime | duration | calendarDuration
Complex Number Support: Yes

rowTimes — Times associated with rows of timetable

datetime vector | duration vector

Times associated with rows of a timetable, specified as a datetime vector or a duration vector. Each time labels a row in the output timetable. The time values in rowTimes do not need to be unique, sorted, or regular.

Fs — Sample rate

positive numeric scalar

Sample rate, specified as a positive numeric scalar. Fs specifies the number of samples per second (Hz).

dt — Time step

datetime scalar | duration scalar

Time step, specified as a datetime scalar or duration scalar.

Data Types: datetime | duration | calendarDuration

t0 — Start time

datetime scalar | duration scalar

Start time, specified as a datetime scalar or duration scalar.

• If t0 is a datetime value, then the row times of TT are datetime values.

• If t0 is a duration, then the row times are durations.

If the time step dt is a calendar duration value, then t0 must be a datetime value.

Data Types: datetime | duration

varNames — Names of variables

cell array of character vectors | string array

Names of the variables in the output timetable, specified as a cell array of character vectors or a string array. The number of names in varNames must equal the number of variables.

Output Arguments

TT — Output timetable

timetable

Output timetable. The timetable can store metadata such as descriptions, variable units, variable names, and row times. For more information, see the Properties section of timetable.

Compatibility Considerations

'SamplingRate' is not recommended

Not recommended starting in R2018b

The 'SamplingRate' name-value pair argument is not recommended. Use 'SampleRate' instead. The corresponding timetable property is also named SampleRate.

For backward compatibility, you still can specify 'SamplingRate' as the name of the name-value pair. However, the value is assigned to the SampleRate property.

Extended Capabilities

Tall Arrays

Calculate with arrays that have more rows than fit in memory.

This function fully supports tall arrays. For more information, see Tall Arrays.