列表MATLAB中的项目数

Question

argument = [new_letter_A, new_letter_B, new_letter_C, new_letter_D, new_letter_E];

In Python, I can use len(argument) to find the number of items in the array above. Is there an easy way to accomplish the same thing in MATLAB? (I want this to return '5'.)Thank you.

Answer 1

You should either store your vectors as rows and get the size of the first dimension

argument = [new_letter_A; new_letter_B; new_letter_C; new_letter_D; new_letter_E];
size(argument, 1)

Or you can store each vector as a cell in a cell array

argument = {new_letter_A, new_letter_B, new_letter_C, new_letter_D, new_letter_E};
length(argument)

One of the advantages of the second approach is that you can use cellfun to apply a function to each letter (for example, if you had a function which you were using to compress each letter...)

Answer 2

使用length功能：

length(argument)

Answer 3

There are many way to do this such as numel , length and size . MATLAB works with 2d arrays/matrices.

If your matrix is nxm :

• numel would be n*m
• length would be max(n, m)
• size would be n. You can use size(argument, 2) to get m.

In the case of 1-d array, they are all the same.