The variance function of matrix in MATLAB--a reference to online data

>> a = [0.0579 0.1389 0.2722 0.4451
0.3529 0.2028 0.1988 0.9318
0.8132 0.1987 0.0153 0.4660
0.0099 0.6038 0.7468 0.4186];
B1 = var (a); % default to ask for
B2 = var (a, 0); % default formula (with N-1)
C1 = VAR (a, 1); % additional formula (with N)
D1 = var (a, 0, 1); % operation on each column
D2 = var (A, 0, 2); % Action per line
D3 = var (a '); % test
E = Var (a (:));% operation of the matrix by direct access to the storage of the matrix
>> B1
B1 =
0.1362 0.0457 0.0971 0.0601
>> B2
B2 =
0.1362 0.0457 0.0971 0.0601
>> C1
C1 =
0.1022 0.0343 0.0729 0.0450
>> D1
D1 =
0.1362 0.0457 0.0971 0.0601
>> D2
D2 =
0.0287
0.1208
0.1203
0.1021
>> D3
D3 =
0.0287 0.1208 0.1203 0.1021
>> E
E =
0.0819
The final use of a (:) is a good way to get a line representation of a matrix

The variance function of matrix in MATLAB--a reference to online data