Matlab programming example: how to count the number of elements in a cell array

Problem description

There are multiple repeating elements in an array , Such as {' Basketball ', ' football ', ' Table Tennis ', ' football ', ' Table Tennis ', ' football ', ' Volleyball '}, How to count the number of each ball ? ( Please think for a few seconds !!)

A feasible method

• Use unique() Function to construct a sphere dictionary ( No duplicates ),
• Use strcmp() Functions and find() Function to judge in turn balls The category of each element in the , Increase the number of corresponding categories .

The code is as follows :

balls = {' Basketball ', ' football ', ' Table Tennis ', ' football ', ' Table Tennis ', ' football ', ' Volleyball '};
dict_ball = unique(balls);
count_ball = zeros(size(dict_ball));
for k = 1:length(balls)
    idx = find(strcmp(balls{k}, dict_ball));
    count_ball(idx) = count_ball(idx)+1;
end

The operation results are as follows :

Use pie(), pie3() Draw the pie chart :

pie(count_ball,dict_ball);
title(' Proportion of balls ')

If you have a better way , Welcome to the comment area !