MATLAB: How to access 'Duration' datatype

Question

Consider the following example

xDATA = data_timestamp;
[~,~,Days,Hour,Min,~] = datevec(xDATA(2:end) - xDATA(1:end - 1));
BadSamplingTime = find((Days)> 0 | (Hour)> 0 |(Min)> 5 );

In which xData contains a vector of time stamps and I am trying to find the samples with sampling time greater than 5 mins in between , the algorithm works fine but it creates 3 extra vectors for the data as big as my timestamp vector(the size to time stamp vector is pretty huge) whereas if I do this

DurationTime = xDATA(2:end) - xDATA(1:end - 1);

Instead of the second line it will just create one vector of same length of 'duration' data type which will be much easier to handle because but the problem I cant seem to access each index of the duration data type for example

DurationTime(5,1)

ans = 

   26:00:01

I need to access this 26 hours part , does anyone have any idea how to do that ? or a better suggestion

Matt Matt · Accepted Answer · 2016-06-03T12:04:49

You can create a duration-object and then use it to compare it with the duration vector DurationTime. The result of a>b is a logical vector that can be directly used to index the elements of DurationTime and thus giving you all the values where the duration is greater than 5 minutes.
Sidenote: You can calculate the difference/duration directly with diff.

Code:

% create example data
xDATA = (([0:4,4+26*60,4+26*60+1:4+26*60+5])/24/60+datetime('now')).';

% calculate the durations
DurationTime = xDATA(2:end) - xDATA(1:end-1);      % as in the question
%DurationTime = diff(xDATA);                       % alternative

% get index and values of all durations greater than 5 minutes
ind = find(DurationTime>duration(0,5,0))
DurationTime(ind)

% get values of all durations greater than 5 minutes (direct solution, if no index needed)
DurationTime(DurationTime>duration(0,5,0));

Result:

ind =

     5

ans = 

   26:00:00

MATLAB: How to access 'Duration' datatype

1 Answers