# how to create logical matrix directly in matlab

## how to create logical matrix directly in matlab

Use false directly:

``````a = false(10,10);
``````

In Matlab, there are a few constants that are actually matrix-generating commands. They are:

``````true(10);   true(n,m,k,..);   % for an all-true  10-by-10 or n-by-m-by-k-by-...matrix
false(10);  false(n,m,k,..);  % for an all-false 10-by-10 or n-by-m-by-k-by-...matrix
inf(10);    inf(n,m,k,..);    % for an all-inf   10-by-10 or n-by-m-by-k-by-...matrix
nan(10);    nan(n,m,k,..);    % for an all-nan   10-by-10 or n-by-m-by-k-by-...matrix
``````

The constant forms are basically just aliases:

``````a = inf;   % alias for a = inf(1);
b = true;  % alias for b = true(1);
``````

etc. Also, here are some more things that cannot be repeated enough:

``````rand(10);  rand(n,m,k,..);    % for an all-random 10-by-10 or n-by-m-by-k-by-...matrix
zeros(10); zeros(n,m,k,..);   % for an all-zero   10-by-10 or n-by-m-by-k-by-...matrix
zeros(n,m,k,...,uint8);     % for an all-zero   n-by-m-by-k-by-...matrix of type uint8
ones(10); zeros(n,m,k,..);    % for an all-one    10-by-10 or n-by-m-by-k-by-...matrix
ones(n,m,k,...,uint8);      % for an all-one    n-by-m-by-k-by-...matrix of type uint8
eye(10); eye(n,m,uint8);    % for an identity matrix of type uint8 of 10-by-10 or n-by-m
``````

#### how to create logical matrix directly in matlab

Matlabs logical data type does not appear to have a constructor other than the `logical` function itself. That being said, you can effectively typecast a double array as a logical array very easily, where all nonzero values become logic 1 and all zeros logic 0:

``````A = [1 0 2; -1 0 0; 0 1.53 -100.00]

B = logical(A)

B =
1     0     1
1     0     0
0     1     1
``````

You can obviously condense this assignment to one line if youd like, so it becomes nearly as simple as assigning any other data type.