Study notes 123-matlab calculate the mean, variance, standard deviation

1, mean (X): A matrix column average seek; mean (X, 2) row of the matrix X average seek; if X is a vector, mean (X) X returns average.

2, the variance: Y = var (X, 0,1 ): find the variance column vector of matrix X; Y = var (X, 0,2 ): find the row vector variance matrix X

       at time reading image pixels, to converted to a double-type: X = double (X)

. 3, standard deviation: std, mean square error, std (X, 0,1) seeking a column vector variance, std (X, 0,2) seeking row vector variance.