18-matlab知识点复习一

clc;
clear;

%% 输出
clc, clear;
fprintf(\'%.19f\', pi);
fprintf(\'%d\', 110);
inf
pi
disp([1,3,5])  
disp(\'a\');
disp(num2str(12));    %numstr()是将其他类型的变量转化成字符串的形式
disp(str2num(\'234\')); 
a = str2num(\'1\')
b = a + 1

%% 输入：
clc, clear;
a=input(\'please input a number：\')
b=input(\'请输入一个字符串:\',\'s\')
c=input(\'请输入一个矩阵:\')  % 输入要带中括号：[1,2]

%% 矩阵生成函数：
clc, clear;
A = zeros(3,4)
B = ones(3,4)
C = eye(3,3) % 对角矩阵

%% 数组字符串切割
clc, clear;
s=[\'aa\', \',\', \'23\', \',44\']
a = s(2:3)
s2 = \'1232323aaaa\'
b = s2(5:9)

%% 循环：
clc;
clear;
a=[2 5 6 9888 8 86 4 5 6 65 3 54];
len = size(a,2);
max_n = -1;
for i = 1:len
    if a(i) > max_n
        max_n = a(i);
    end
end
fprintf(\'for最大的数: %d\n\', max_n);
max_n = -1;
i = 1;
while i <= len 
    if a(i) > max_n
        max_n = a(i);
    end
    i = i + 1;
end
fprintf(\'while最大的数: %d\n\', max_n);

%% 调用函数：
clc;
clear;
[s,l] = circle(2) %调用

-----------------------
function [s,l] = circle(r)
    s = pi * (r ^ 2);
    l = 2 * pi * r;
end