Conditional retime method in a timetable

Hi,

I'm looking for a way to create a conditional retime (at a fixed fequency, let's say 1 Hz) method based on the actual values of a variable Var in a timetable T.

In the time table T attached::

if Var transitions from 0 -> 1, 0 -> 2, 1 -> 2 or 2 -> 1 use method next,

if Var transitions from 1 -> 0 or 2 -> 0 use method previous.

Is there a way?

Thanks in advance.

Answer 1

[Voss]

Maybe something like this:

S = load('timetable.mat');
T2 = S.T2;

dt = 1;

t = seconds(T2.Time);
N = round((t(end)-t(1))/dt)+1;

ti = linspace(t(1),t(end),N).';
Vari = zeros(N,1);

for ii = 1:numel(t)-1
    Vari(ti>t(ii) & ti<=t(ii+1)) = T2.Var(ii+logical(T2.Var(ii+1)));
end

% Another way to write that loop; may be easier to understand:
% 
% for ii = 1:numel(t)-1
% 
%     idx = ti>t(ii) & ti<=t(ii+1);
% 
%     if T2.Var(ii+1) == 0 % transition ends with 0 
%                          % (i.e., 0->0, 1->0, 2->0)
% 
%         Vari(idx) = T2.Var(ii); % use previous
% 
%     else                 % transition ends with 1 or 2 
%                          % (i.e., 0->1, 0->2, 1->1, 1->2, 2->1, 2->2)
% 
%         Vari(idx) = T2.Var(ii+1); % use next
% 
%     end
% 
% end

T2_retimed = timetable(seconds(ti),Vari, ...
    'VariableNames',T2.Properties.VariableNames);

figure
plot(T2.Time,T2.Var,T2_retimed.Time,T2_retimed.Var)
legend({'Original','Retimed'},'Location','NorthWest')

[Gabi]

Thanks, it surely works.

[Voss]

You're welcome!