I want to skip one step

Hi I have a matrix,I want the code to skip executing statements if the row is repeated. Thanks

[the cyclist]

You are expecting us to guess too many details of what you are doing, which will likely lead to us wasting a lot of our time. Please provide a small example of the code you are using, where you want the skip to be inserted.

[Geoff Hayes]

yousef - please define what you mean by repeated. Do you mean that the current row repeats with a previous row in the matrix (so if you are considering row i then it is repeated if there is at least one row in the matrix from 1 to i-1 that is identical to row i? Or do you mean that row i is repeated in any row of the matrix from 1 to i-1 or i+1 to m (where m is the number of rows in your matrix).

Answer 1

[yousef Yousef]

Geof ,please have a look on this file. Thanks

Answer 2

[Geoff Hayes]

yousef - please remove/delete your answer (as it isn't an answer to your question). I've attached your pdf to this one.

From the document, your xx is shown as:

xx =

     1     7     0     0
     2    10     0     0
     3     0     0     0
     4     0     0     0
     5     0     0     0
     6     0     0     0
     1     7     0     0
     8     0     0     0
     9     0     0     0
     2    10     0     0

where any element in the first column represents an index (into ww) of the first occurrence of that value in ww. Here is your ww:

ww =

     6     7     5     9     8    10     6     4     2     7

From the above, we see that x(1:6,1) are unique indicating that the first six values of ww are unique. The seventh value, xx(7,1), is 1, indicating that ww(7)==ww(1). x(8:9,1) are unique to any previous value in this first column, and xx(10,1) is 2, indicating that ww(10)==ww(2).

Thus if you are iterating over the first column in xx, you know if you have a repeated value in ww (not quite the row you mentioned above) if its index value, xx(i,1) is less than i:

[m,n] = size(xx);
for i=1:m
  if xx(i,1)==i
     % we have not encountered this number in ww before (i.e. ww(xx(i,1)) is unique thus far)
     % so do stuff
  else
     % xx(i,1) is less than i, so we must have encountered this index in ww already
     % do nothing
     continue;  % not needed, but just to be clear nothing happens here
  end
end

[yousef Yousef]

Thanks Geof for your help.It works well but still needs very small tricks to get the desired result. what about to make it more general ,the code will compare the hall rows to find out the row is repeated or not via this step x2=xx(i,:); out = ismember(xx,xx(i,:),'rows'); then use out Please check it out

[Geoff Hayes]

yousef - I don't understand what you mean by "hall rows". For sure if you think that what you propose might work, then by all means try it out! :)

[yousef Yousef]

     Thanks Geof,I really appreciate your contact with me,I want it to be in general form .
      Your code is done based on comparing the first element of the row x(i,1)=i
      what about if 
      xx=

           1     2     3
           4     5     6
           1     2     3
           3     2     4
           1     2     3
           3     2     1
           1     3     2 
  Thanks

[yousef Yousef]

Thanks Geof,I really appreciate your contact with me,I want it to be in general form .

Your code is done based on comparing the first element of the row x(i,1)=i
      what about if 
      xx=
           1     2     3
           4     5     6
           1     2     3
           3     2     4
           1     2     3
           3     2     1
           1     3     2 
  Thanks

[yousef Yousef]

what about this one:
  [~,~,A] = unique(xx,'rows','stable');
  [n, bin] = histc(A, unique(A));
  bin =
       1
       2
       1
       3
       1
       4
       5
What do you think about it?Is there some thing better?
Thanks