finding the duration of a sequence of data

I need to find the duration of a sequence of data values that represents head yaw movements .

where the positive values are head looking to right and negative values are head looking to left .

the below signal has different duration of looking right and left. How can I find these duration ?

Answer 1

[Andy]

positive = (data>0); % Identifies when the head is to the right.

pos_count = sum(positive); % gives you the number of measurements.

If you have the logging frequency it is easy to calculate time.

The similar code can be used for determining left movement. Instead of using data>0 use another number to give a bit of tolerance on what constitutes looking ahead.

[sarmad m]

Thanks ,but how the duration of each sequence can be found as shown in the image ?

Answer 2

[Andrei Bobrov]

d = csvread('case2.csv');
d1 = d(d ~= 0);

t = d1 > 0;
tt = diff([1;t(:)]) ~= 0;
out = accumarray(cumsum(tt),d1);

[sarmad m]

Thanks @ y Andrei Bobrov . When I plot out I get this plot , is out values are the duration for each sequence of values ?

[Andrei Bobrov]

another variant

t = d ~= 0;
d1 = d(t);
t1 = d1 > 0;
tt = [true;diff(t1)~=0];
ii = cumsum(tt);
out = accumarray(ii,1).*sign(d1(tt));

[sarmad m]

the plot below shows a signal and (out) plot . out values are :

-25 122 -130 25 -7 138 -17 37 -53 58 -46 so do they represent the duration of each sequence ?