Mutiple Time series synchronization
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Hi
I want to synchronize multiple time series
Can any suggest how to do it.
Thanks
9 个评论
Life is Wonderful
2019-8-14
Guillaume
2019-8-14
The synchrosize function (for timeseries) has several synchronisation methods, which one do you want to use?
Note that synchronisation does not affect the duration of a series, it only changes at which period that series is sampled.
If you want to make a time series longer (in period, not number of samples) then you will have to extrapolate. If you want to make it shorter, you'll simply have to clip it.
Life is Wonderful
2019-8-14
编辑：Life is Wonderful
2019-8-14
Guillaume
2019-8-14
Right, so you don't have timeseries. Perhaps, firmware_FAFTSetup_DEBUG is a timetable? Or a table? Or maybe a plain structure? In any case, it's important to use the correct term.
In order to extrapolate, you need a fit for your data. What sort of fitting function are you planning to use?
Life is Wonderful
2019-8-14
编辑：Life is Wonderful
2019-8-14
Guillaume
2019-8-14
The synchronisation method applies to the timing of your data, not to the data itself. You're not going to extrapolate a sinusoid the same way you extrapolate a line.
Life is Wonderful
2019-8-14
Life is Wonderful
2019-8-15
Guillaume
2019-8-15
My goal is to get a common time series with text data
If it's textual data, I have no idea why you were asking about extrapolation. How do you extrapolate text?
Anyway, to synchronize several timetables you'd simply do it in a loop. I can show you how it's done once I understand what the inputs are. So far, you seem to have shown date variables, a timeseries or timetable needs date and data to be useful.
I'm not even sure what kind of data you have, so please state whether it's timeseries, timetable, table or something else.
采纳的回答
Guillaume
2019-8-16
I think this does what you want:
contentfields = fieldnames(Content);
for fieldidx = 1:numel(contentfields) %iterate over each field of Content
structtable = struct2cell(Content.(contentfields{fieldidx})); %extract the structure within the field by converting it to cell array (avoids having to work out what its name is)
structtimetable = table2timetable(structtable{1}(:, {'Date', 'Message'})); %convert to timetable, only keeping Date and Message
structtimetable.Properties.VariableNames{1} = sprintf('Message_%s', contentfields{fieldidx}); %rename Message variable so we know where it came from
structtimetable = rmmissing(structtimetable); %remove invalid rows to avoid problems with synchronize
if fieldidx == 1
joinedtimetable = structtimetable; %1st time, create output
else
joinedtimetable = synchronize(joinedtimetable, structtimetable, 'union'); %subsequent times, synchronize. Choose whichever method is prefered
end
end
The main issue is that some (all?) of your tables contain rows with NaT which cause problem with synchronisation. You may want to investigate that. I've removed these rows here.
11 个评论
Life is Wonderful
2019-8-16
Life is Wonderful
2019-8-20
编辑：Life is Wonderful
2019-8-22
Life is Wonderful
2019-8-20
Rik
2019-8-21
Comment posted as flag by sriram shastry:
Synchronization is not working as expected.Please help me.
Life is Wonderful
2019-8-22
编辑：Life is Wonderful
2019-8-22
Guillaume
2019-8-22
I'm sure we discussed this before. You have a strange concept of time. A date is a point in time, a duration is the distance between two dates and to me it doesn't make sense to take one part of a date and say it's a duration. I could understand subtracting the first date of a table from all the other dates in the same table to get a duration (time ellapsed since the start of the log) but just taking the hour/minute/second part of a date and calling that a duration makes no sense to me.
Anyway, if that's what you want, it's trivial to do:
contentfields = fieldnames(Content);
for fieldidx = 1:numel(contentfields) %iterate over each field of Content
structtable = struct2cell(Content.(contentfields{fieldidx})); %extract the structure within the field by converting it to cell array (avoids having to work out what its name is)
structtable = structtable{1}; %get the table out of the cell
structtable.Date = duration(structtable.Date.Hour, structtable.Date.Minute, structtable.Date.Second); %extract h/m/s and make that a duration. This makes no sense to me!
structtable.Properties.VariableNames{1} = 'WeirdDuration'; %rename the time column
structtimetable = table2timetable(structtable(:, {'WeirdDuration', 'Message'})); %convert to timetable, only keeping Date and Message
structtimetable.Properties.VariableNames{1} = sprintf('Message_%s', contentfields{fieldidx}); %rename Message variable so we know where it came from
structtimetable = rmmissing(structtimetable); %remove invalid rows to avoid problems with synchronize
if fieldidx == 1
joinedtimetable = structtimetable; %1st time, create output
else
joinedtimetable = synchronize(joinedtimetable, structtimetable, 'union'); %subsequent times, synchronize. Choose whichever method is prefered
end
end
Life is Wonderful
2019-8-22
编辑：Life is Wonderful
2019-8-22
Guillaume
2019-8-22
Note that subtracting the first date of a table from all the other dates in the same table to get a duration is not what I have done above. I've just extract the hour/minute/seconds and made that a duration, as you asked (even though it makes no sense to me).
If you do want to subtract the first date to convert to duration then change the line:
structtable.Date = duration(structtable.Date.Hour, structtable.Date.Minute, structtable.Date.Second); %extract h/m/s and make that a duration. This makes no sense to me!
to
structtable.Date = structtable.Date - structtable.Date(1); %elapsed time since start of log.
Life is Wonderful
2019-8-22
Guillaume
2019-8-22
Nowhere probably. If it's not visible, it's most likely because the default duration format doesn't display it. You can easily change the Format of the variable to whatever you want:
joinedtimetable.RowTimes.Format = 'hh:mm:ss.SSS';
Life is Wonderful
2019-8-25
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