CODEWITHSUNDEEP
matlab
Saghir Ahmed
Saghir Ahmed

Reputation: 7

Delete all those columns from matrix which contains all values are '0' in matlab

I have a large matrix data which are based on row and columns, I want to delete all those columns which contain all values are 0 in MATLAB.

Upvotes: 0

Views: 53

Answers (1)

Suever
Suever

Reputation: 65430

You can use all with a second input to check which columns have all zeros. This will return a logical array that is true when all rows of a given column satisfy a condition and false otherwise. You can then use the inverse of the result as a logical index to select only the columns that don't satisfy this criteria

data = data(:, ~all(data == 0, 1));

Alternately, you could use any in a similar way. any will return a logical array that is true when there is any row in a column that satisfies the condition and false otherwise.

data = data(:, any(data ~= 0, 1));

This one can be simplified even further though since internally, any will cast data as a logical value turning any non-zero value into true and any zero value into `false.

data = data(:, any(data, 1));

If you are working with floating point numbers, you'll want to use a very small epsilon rather than comparing numbers directly to 0

data = data(:, ~all(abs(data) < eps, 1));
data = data(:, any(abs(data) > eps, 1));

Upvotes: 1

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