Matlab中二维矩阵元素的直方图

Question

I am wondering if there is any build in function or an easy way to plot a histogram of elements of a 2d array .

For example, if A=rand(100,1) , then A is an 1D array , and hist(A) can do the histogram.

However, what if A=rand(100,100) , and I would like to make a histogram on elements of A , just like treating each element in A as an element on a 1D array . Is there a easy way to do so?

Answer 1

你只需要将A重塑为一个向量，然后就像往常一样使用hist ：

hist(A(:))

Answer 2

This command will do what you want:

hist(reshape(A, prod(size(A)), 1))

What it does is create a vector out of the matrix A by reshaping it into a matrix with one column and a number of rows equal to the number of elements of A:

prod(size(A)) = number_of_columns(A) * number_of_rows(A)

Or the short way:

hist(A(:))

This takes every element of A in sequence and thus also generates a vector.