how to delete a row if a number is repeated 4 times or 3 times

i have a matrix M=65005*5

there are certain rows in which number is repeated twice, thrice or four times. i want to delete that row from matrix.

for example

M=[1 1 1 1 16; 2 5 6 4 16; 2 2 2 6 5];

if 4 (because there is 4 repested number in 1st row) is written than 1st row will be deleted

when 3 (there is 3 repeated number in 3rd row) is written than 3rd row will be deleted.

Thanks in advance

Answer 1

[Mili Goyal]

Checking for the repeating entries in every row and then deleting itcan be one of the straightforward approach. Following is the code for the same.

%% Code

i = 1;

while i <= size(M,1)

if(length(M(i, :)) ~= length(unique(M(i, :)))) % checking for the repeated entry.

M(i, :) = []; % deleting the row.

else

i = i+1;

end

end

%%

The above will return M = [2 5 6 4 16] as the ans for the example M given in the question.

[Sun Heat]

thanks for your reply, i update my question for better understand

for example

M=[1 1 1 1 16; 2 5 6 4 16; 2 2 2 6 5]

if 4 (because there is 4 repested number in 1st row) is written than 1st row will be deleted not 2nd, 3rd and 4th row.

when 3 (there is 3 repeated number in 3rd row) is written than 3rd row will be deleted not 1st, 4th and 2nd row.

[Mili Goyal]

So you mean that if 4 is given as input, the first row should be deleted?

Also, are the numbers repeated only 2, 3 and 4 times?

[Sun Heat]

Yes mili.... thanks for reply The first question ask by you is my major concern..."So you mean that if 4 is given as input, the first row should be deleted?"

[Mili Goyal]

Did you try storing the number of occurances of repeating numbers for all the rows in an array and then iterating through them depending upon the input and deleting rows?