Find value in another cell array based on condition

I have a folder containing the following files:

Every file has the same format, but for a different time step:

First (headerline): N, time, xmin, ymin, zmin, xmax, ymax, zmax

N Lines: x, y, z, vx, vy, vz, rad, q1, q2, q3, omex, omey, omez, xi

where N is the number of particles.

(x,y,z) are the coordinates

(vx, vy, vz) are the velocities

rad is radius of particle

time is time step

I have split the format into 3 seperate cell arrays as follow:

expData with format x, y, z, rad, z +rad, vol

vol is the volume of the particle, which I calculated from radius

velData with format vx, vy, vz, mag

runData with N, time, xmin, ymin, zmin, xmax, ymax, zmax

%% Loading the data
rhoPart = 2500;

files = dir(fullfile(uigetdir,'*.data*'));
[~,Index] = natsort({files.name});
files = files(Index);
expData = cell(length(files),1);
k = 1;
for i = 1:length(files)
    fid = fopen(fullfile(files(i).folder,files(i).name),'r');
    %% Reading the data
    % Read all the data from the file
    dataRead = textscan(fid,'%f %f %f %f %f %f %f %f %f %f %f %f %f %f','HeaderLines',1);
    frewind(fid);
    % Write headerline N, time, xmin, ymin, zmin, xmax, ymax, zmax
    runData{k} = strsplit(fgetl(fid), ' ');
    % Write only the x, y, and z components of the particles, particle radius,
    % z component+ particle radius and volume of the particle
    expData{k} = [dataRead{1}(:,1) dataRead{2}(:,1) dataRead{3}(:,1) dataRead{7}(:,1) dataRead{3}(:,1)+dataRead{7}(:,1) rhoPart*(4/3)*pi*(dataRead{7}(:,1).^3)];
    % Write only the vx,vy,vz of the particles and magnitude
    velData{k} = [dataRead{4}(:,1) dataRead{5}(:,1) dataRead{6}(:,1) sqrt(dataRead{4}(:,1).^2 + dataRead{5}(:,1).^2 + dataRead{6}(:,1).^2)];
    fclose(fid);
    k = k + 1;
end

With the following code I calculated the total mass of particles for every time step:

for i = 1:length(files)
    %Count the number of particles in the silo (silo outlet is located at z =
    %0.3 m)
    particlesInSilo{i} = find(expData{i,1}(:,3)>0.3);
    % Multiply the number of particles with the volume of the particle
    siloMass{i} = sum(expData{i,1}(cell2mat(particlesInSilo(i)),6));
end

Thus,

the total mass of siloV1.data.1787 is 3.6317 kg at time step 1.900577757 s

the total mass of siloV1.data.1820 is 3.4481 kg at time step 1.935675163 s

....

the total mass of siloV1.data.2714 is 0 kg at time step 2.886495821 s

With the following code I found when the total mass is 0 kg:

for i = 1:length(files)
siloMass_zero = find(siloMass{1,i}(:)<=0);
end

I want to find the corresponding time step when the total mass is 0 kg. How can I do that?

Note that the codes I presented in this post are only sections of my code.

[Mario Malic]

Hi Tessa,

All of your read data are numbers, so, it's better to save it in a numeric array, instead of cells. This link might help, if you decide to change to num arrays.

Otherwise, there's a function called cellfun that applies a function to contents of cell array.

cellfun(@find, siloMass) %something like this

[Tessa Kol]

I created a num arrays as you said, i.e. siloMass_d and time_d (see pictures below). Every column is 1 simulation. One simulation contains 5 data files. Each data file contains the same format of data but at a different time step.

Thus, simulation 1:

At t = 6.1446 seconds the total mass is 0.1674 kg

At t = 6.1496 seconds the total mass is 0.1674 kg

Simulation 2

At t = 4.6397 seconds the total mass is 0.3042 kg

At t = 4.6447 seconds the total mass is 0.3042 kg

..etc.

In total I have 81 simulations

With the code below I managed to in each simulation where the total mass is equal or below 0.17 kg.

for i = 1:81 %Number of simulations
        siloMass_zero{i} = find(siloMass_d(:,i)<=0.17);
end

Now I want to find the corresponding time. How can I do that?

[Tessa Kol]

I found the solution already:

for i = 1:N_run
        siloMass_zero{i} = find(siloMass_d(:,i)<=0);
        time_dischargerange{i} = time_d(siloMass_zero{1,i});
        time_dischrage{i} = time_dischargerange{1,i}(1,1);
end

But thank you for your input!

[Mario Malic]

Great work!

You can post an answer to your question and accept it yourself so other people can find it useful if they encounter problem similar to yours.

Answer 1

[Tessa Kol]

Here the code that was succesfull for me:

for i = 1:N_run %Number of simulation runs, which is for me 81 simulations
        siloMass_zero{i} = find(siloMass_d(:,i)<=0); % Find all the values in the numeric array that are smaller than or equal to zero
        time_dischargerange{i} = time_d(siloMass_zero{1,i}); % Find the corresponding time by indexing
        time_dischrage{i} = time_dischargerange{1,i}(1,1); % Extract only the first time step value, if multiple time steps are found
end