table2timetable with Time as double

Hello,

I have the following table :

The data come from a CAN trace, hence the varialbe time step.

My final goal is to do some analysis on the data.

My understanding is that it would be easier with a timetable and a resampling.

But I fail to convert this to a timetable :

my_timetable=table2timetable(my_traces(4).ewellix_num_data.fbk.ID04);
Error using table2timetable (line 59)
Input table must contain datetime or duration vector for row times.

my_timetable=table2timetable(my_traces(4).ewellix_num_data.fbk.ID04,"RowTimes","Time");
Error using table2timetable (line 135)
Row times must be datetime or duration vector.

I have the feeling that the type of Time variable is not correct but I had no luck trying to convert it.

Thanks

Answer 1

[Stephen23]

You need to convert the TIME column/variable to e.g. a DURATION object.

For example, if the time is given in seconds then you could use the SECONDS function:

https://www.mathworks.com/help/matlab/ref/duration.seconds.html

For example, where T is your table:

T.Time = seconds(T.Time)

[John Math]

thanks, I tried it last night without sucess, worked like a charm today. probably I was the source of the problem.

Answer 2

[Star Strider]

The resample function works with timetable arrays. See Resample Nonuniformly Sampled Data in Timetable for an example.

Timesec = sort(rand(30,1));
Time = datetime([zeros(numel(Timesec),5) Timesec], 'Format','ss.SSSS');
Position = sin(2*pi*Timesec) + randn(size(Timesec))/10;

TTx = timetable(Time,Position)

TTx = 30x1 timetable
     Time      Position
    _______    ________

    00.0292     0.10935
    00.0516     0.38739
    00.0741     0.44271
    00.1055     0.68116
    00.1132     0.60149
    00.1546     0.90425
    00.1642     0.86509
    00.2479     0.97991
    00.2521     0.98361
    00.2886      1.1611
    00.3057     0.75028
    00.3511     0.82205
    00.3683     0.70712
    00.3853      0.6059
    00.4340     0.40684
    00.5415    -0.17432

TTy = resample(TTx)

TTy = 30x1 timetable
     Time      Position 
    _______    _________

    00.0292      0.10935
    00.0623      0.41367
    00.0954      0.60453
    00.1285      0.71319
    00.1616      0.87583
    00.1946      0.90688
    00.2277      0.95226
    00.2608       1.0258
    00.2939       1.0342
    00.3270      0.78389
    00.3600      0.76228
    00.3931      0.57409
    00.4262      0.43887
    00.4593      0.27028
    00.4924     0.091338
    00.5254    -0.087604

figure
plot(TTx.Time, TTx.Position, 'o-', 'DisplayName','Original Data')
hold on
plot(TTy.Time, TTy.Position, 's-', 'DisplayName','Resampled Data')
hold off
grid
xlabel('Time')
ylabel('Position')
legend('Location','best')

.