How to calculate residence time?

Hi,

I have a time column in picoseconds and 442 distance columns measured in nanometres. I know how to extract the time points that meet the distance threshold I have set.

x = xlsread('10_1.xlsx')
x = x(x(:,2)<=0.5,:);

I want to calculate the total residence time for each of the columns. How can I do this?

Akash

[dpb]

Dunno...what's the working definition of "residence time" here?

[Akash Pandya]

So the residence time refers to the time a small molecule is <=0.5 nanometers away from a protein. I want to find the total time where the distance (nm) meets this criteria.

Akash

Answer 1

[Image Analyst]

Use regionprops() and ask for PixelIdxList. Then use PixelIdxList(end) - PixelIdxList(1) for each region found. Something like

props = regionprops(vec, 'PixelIdxList');  % Vec is a 1-d list of binary (boolean/logical) data of whether x is above 0.5 or not.
% Now find the delta time for all regions found in this vector, vec.
for k = 1 : length(props)
    startingIndex = props(k).PixelIdxList(1);
    endingIndex   = props(k).PixelIdxList(end);
    deltaTime(k) = x(endingIndex) - x(startingIndex); % x is the time vector
end

Attach '10_1.xlsx' if you need more help.