Loop Question for particle

I have following data I want to use first 2 columns in a for loop to detect the particles for which there is no contact. first 2 columns show 2 particles which are in contact. How can I get an output in tabular form. Basically i want to detect those particles for which there is no contact. Particles are 484 and total number of contacts is 956.

1    324  0.720141865396207E+00  0.000000000000000E+00  0  0.000000000000000E+00
     1    439  0.940050831127248E+00  0.000000000000000E+00  0  0.000000000000000E+00
     1    441  0.131609998985588E+01  0.000000000000000E+00  0  0.000000000000000E+00
     2     25  0.363379567116406E+00 -0.000000000000000E+00  0  0.000000000000000E+00
     2     89  0.753090369602638E+00  0.000000000000000E+00  0  0.000000000000000E+00
     2    109  0.851303474754872E+00  0.000000000000000E+00  0  0.000000000000000E+00
     2    220  0.898508917122121E+00 -0.000000000000000E+00  0  0.000000000000000E+00
     3      6  0.890341369366110E+00  0.000000000000000E+00  0  0.000000000000000E+00
     3     26  0.283864328102457E+00  0.000000000000000E+00  0  0.000000000000000E+00

Data = importdata('dem22.txt');
Particle1 = Data(:,1);
Particle2 = Data(:,2);
number_of_particles = 484
total_contacts = length(Particle1);
Contact = Particle1+Particle2
Table = cell(956,2);
for i = 1:1:ncont;
    j = 1:npa;
    Contact(ncont,1) = i;
    i = i+1;
    Contact(ncont,2) = j;
    j=j+1;
    Table(i,:) = {i j};
    fprintf('%d %d\n', Table{i,:});
end

T = table(Contact,npa);

[Geoff Hayes]

shah - do you really want that your code increments the step variable i from within the body of the for loop? Should your j be an array?

for i = 1:1:ncont;
    j = 1:npa;                      % <--- why is this an array?
    ncont(Contact_numbers,1) = i;
    i = i+1;                        % <--- is this intentional? why?
    ncont(Contact_numbers,2) = j;
    j=j+1;
    Table(i,:) = {i j};
    fprintf('%d %d\n', Table{i,:});
end

Also, what tells you if there is no contact? A value of zero? negative one?

[shah nawaz]

I want to show no contact as zero in the form of a table. Sorry first 2 columns show 2 particles which are in contact not the contact numbers.

[Geoff Hayes]

I still don't understand how you determine "no contact" particles. Can you illustrate with an example?

[shah nawaz]

I want to determine those particles which are not in column1 and columns2 and count them. total particles 484

Answer 1

[Reshma Nerella]

Hi,

You can use union and setdiff functions to find out the particles that are not in contact.

Total_Particles - all particles

Particle1 - particles in column 1

Particle2 - particles in column 2

Contacted_Particles=union(Particle1, Particle2 ) - all particles that are in contact

setdiff(Total_Particles,Contacted_Particles) - gives particles that are not in contact.

Total_Particles, Particle1, Particle2 are all arrays with particle numbers