Identify lines that have a repetition (unique function)

From the attached file, I applied this code to eliminate repeated rows:

a=table2array(readtable("file.txt"));
[output,ia,ic]=unique(a,'rows','stable')
repetition = ic;

Is it possible to directly identify the lines that have repetition?

For 'file.txt' have something like this:

coordinates repeatability

2.3300000e+02 3.5300000e+02 1.4912281e+00 2

3.5300000e+02 2.9500000e+02 6.4122807e+01 1

Answer 1

[Mathieu NOE]

hello

simply this

now the 4th column is your repetition quantity

a=readmatrix("file.txt");
[output,ia,ic]=unique(a,'rows','stable')

B = unique(ic);
Ncount = histc(ic, B); % this willgive the number of occurences of each unique element

out = [output Ncount]

out =

233.0000 353.0000 1.4912 3.0000

233.0000 352.0000 1.4912 1.0000

353.0000 296.0000 64.1228 1.0000

353.0000 295.0000 64.1228 2.0000

353.0000 216.0000 64.1228 1.0000

121.0000 217.0000 162.5439 1.0000

121.0000 216.0000 162.5439 1.0000

121.0000 215.0000 162.5439 1.0000

119.0000 274.0000 184.9123 1.0000

119.0000 273.0000 184.9123 1.0000

369.0000 176.0000 246.0526 1.0000

371.0000 184.0000 246.0526 1.0000

[Alberto Acri]

I thank you @Mathieu NOE. That's exactly what I was asking.

Could you also tell me how I can display only those rows that have in the fourth column values greater than or equal to 2 listed in 'out'?

For example, from 'out' I would like to save in 'out2' only these:

233 353 1.4912 3

353 295 64.122 2

Thanks!!!

[Mathieu NOE]

simply use logical array to select the appropriate lines

a=readmatrix("file.txt");
[output,ia,ic]=unique(a,'rows','stable')

B = unique(ic);
Ncount = histc(ic, B); % this willgive the number of occurences of each unique element
out = [output Ncount] % the 4th column is your repetition quantity 
idx = Ncount>=2; % logical array : select only lines for which repeat >= 2
out2 = out(idx,:) 

Answer 2

[Jan]

data = [   2.3300000e+02	   3.5300000e+02	   1.4912281e+00	
   2.3300000e+02	   3.5200000e+02	   1.4912281e+00
   3.5300000e+02	   2.9600000e+02	   6.4122807e+01	
   3.5300000e+02	   2.9500000e+02	   6.4122807e+01	
   3.5300000e+02	   2.1600000e+02	   6.4122807e+01	
   1.2100000e+02	   2.1700000e+02	   1.6254386e+02	
   2.3300000e+02	   3.5300000e+02	   1.4912281e+00	
   1.2100000e+02	   2.1600000e+02	   1.6254386e+02	
   1.2100000e+02	   2.1500000e+02	   1.6254386e+02	
   3.5300000e+02	   2.9500000e+02	   6.4122807e+01	
   1.1900000e+02	   2.7400000e+02	   1.8491228e+02	
   1.1900000e+02	   2.7300000e+02	   1.8491228e+02	
   2.3300000e+02	   3.5300000e+02	   1.4912281e+00	
   3.6900000e+02	   1.7600000e+02	   2.4605263e+02
   3.7100000e+02	   1.8400000e+02	   2.4605263e+02];
repeated = isMultipleRow(data)

repeated = 15×1 logical array
   1
   0
   0
   1
   0
   0
   1
   0
   0
   1
   0
   0
   1
   0
   0

function T = isMultipleRow(A)
nA = height(A);
T  = false(nA, 1);
[S, idx] = sortrows(A);
m = [false; ~any(diff(S, 1, 1), 2)];
if any(m)               % Any repeated elements found:
   ini    = strfind(m.', [false, true]);
   m(ini) = true;   % Mark 1st occurence in addition
   T(idx) = m;      % Restore original order
end
end