%%==============I. 清空环境变量及命令==================
clear all % 清除Workspace中的所有变量
clc % 清除Command Window中的所有命令
%%==============II. 变量命令规则=======================
%%
%====1. 变量名区分大小写====
A = 2
a = 3
%%
%====2. 变量名长度不超过63位====
ABCDEFGHIJKLMNOPQRSTUVWXYZ123456ABCDEFGHIJKLMNOPQRSTUVWXYZ123456 = 3
%%
%=====3. 变量名以字母开头，可以由字母、数字和下划线组成，但不能使用标点====
% 3A = 4
% .a = 5
% /b = 5
a_2 = 3
% a.2 = 4
%%
%====4. 变量名应简洁明了，通过变量名可以直观看出变量所表示的物理意义====
A = rand(3,5)
rows = size(A, 1)
cols = size(A, 2)
%%==============III. MATLAB数据类型===========================
%%
%====1. 数字=====
2 + 4
10 - 7
3 * 5
8 / 2
%%
%====2. 字符与字符串====
s = 'a'
abs(s)
char(65)
num2str(65)
str = 'I Love MATLAB & Machine Learning.'
length(str)
doc num2str
%%
%====3. 矩阵=====
A = [1 2 3; 4 5 2; 3 2 7]
B = A'%转置
C = A(:)%列向量
D = inv(A)%逆
A * D
E = zeros(10,5,3)
E(:,:,1) = rand(10,5)
E(:,:,2) = randi(5, 10,5)
E(:,:,3) = randn(10,5)
%%
%====4. 元胞数组====
A = cell(1, 6)
A{2} = eye(3)
A{5} = magic(5)
B = A{5}
%%
%====5. 结构体====
books = struct('name',{{'Machine Learning','Data Mining'}},'price',[30 40])
books.name
books.name(1)
books.name{1}
%%============IV. MATLAB矩阵操作=============================
%%
%=====1. 矩阵的定义与构造====
A = [1 2 3 5 8 5 4 6]
B = 1:2:9
C = repmat(B, 3, 1)%复制，将B复制成3行1列
D = ones(2, 4)
%%
%====2. 矩阵的四则运算=====
A = [1 2 3 4; 5 6 7 8]
B = [1 1 2 2; 2 2 1 1]
C = A + B
D = A - B
E = A * B'%矩阵进行计算
F = A .* B具体数值进行计算
G = A / B % G * B = A G * B * pinv(B) = A * pinv(B) G = A * pinv(B)
H = A ./ B
%%
%====3. 矩阵的下标=====
A = magic(5)
B = A(2,3)
C = A(3,:)
D = A(:,4)
[m, n] = find(A > 20)
%%===============V. MATLAB逻辑与流程控制===============
%%
%====1. if ... else ... end====
A = rand(1,10)
limit = 0.75;
B = (A > limit); % B is a vector of logical values
if any(B)
fprintf('Indices of values > %4.2f: \n', limit);
disp(find(B))%dis输出
else
disp('All values are below the limit.')
end
%%
%====2. for ... end====
k = 10;
hilbert = zeros(k,k); % Preallocate matrix
for m = 1:k
for n = 1:k
hilbert(m,n) = 1/(m+n -1);
end
end
hilbert
%%
%====3. while ... end====
n = 1;
nFactorial = 1;
while nFactorial < 1e100
n = n + 1;
nFactorial = nFactorial * n;
end
n
factorial(69)
factorial(70)
prod(1:69)
prod(1:70)
%%
%====4. switch ... case ... end====
mynumber = input('Enter a number:');
switch mynumber
case -1
disp('negative one');
case 0
disp('zero');
case 1
disp('positive one');
otherwise
disp('other value');
end
%%=============VI. MATLAB脚本与函数文件===============
%%
%=====1. 脚本文件====
myScript
%%
%====2. 函数文件=====
mynumber = input('Enter a number:');
output = myFunction(mynumber)
%%===========VII. MATLAB基本绘图操作==============
%%
%======1. 二维平面绘图==========
x = 0:0.01:2*pi;
y = sin(x);
figure
plot(x, y)
title('y = sin(x)')
xlabel('x')
ylabel('sin(x)')
xlim([0 2*pi])
x = 0:0.01:20;
y1 = 200*exp(-0.05*x).*sin(x);
y2 = 0.8*exp(-0.5*x).*sin(10*x);
figure
[AX,H1,H2] = plotyy(x,y1,x,y2,'plot');%两个纵坐标
set(get(AX(1),'Ylabel'),'String','Slow Decay')
set(get(AX(2),'Ylabel'),'String','Fast Decay')
xlabel('Time (\musec)')
title('Multiple Decay Rates')
set(H1,'LineStyle','--')
set(H2,'LineStyle',':')
%%
%======2. 三维立体绘图=============
t = 0:pi/50:10*pi;
plot3(sin(t),cos(t),t)
xlabel('sin(t)')
ylabel('cos(t)')
zlabel('t')
grid on
axis square
%%
%======3. 图形的保存与导出======
% (1) Edit → Copy Figure
% (2) Toolbar → Save
% (3) print('-depsc','-tiff','-r300','picture1')
% (4) File → Export Setup
%%================VIII. MATLAB文件导入================
%%
%====1. mat格式====
save data.mat x y1 y2
clear all
load data.mat
%%
%====2. txt格式====
M = importdata('myfile.txt');
S = M.data;
save 'data.txt' S -ascii
T = load('data.txt');
isequal(S, T)
%%
%====3. xls格式====
xlswrite('data.xls',S)
W = xlsread('data.xls');
isequal(S, W)
xlswrite('data.xlsx',S)
U = xlsread('data.xlsx');
isequal(S, U)
%%
%====4. csv格式=====
csvwrite('data.csv',S)
V = csvread('data.csv');
isequal(S, V)
