input Output
Use input to get keyboard input:
str=input('Please enter your content')
Use disp to print content to the screen:
disp(['This is your content', num2str(s)])
>> s=input('请输入您的内容')
请输入您的内容22
s =
22
>> s=input('请输入您的内容:')
请输入您的内容:22
s =
22
>> disp(['这是您的内容',num2str(s)])
这是您的内容22
Use the fprintf command to format content with quotes: similar to the c language
fprintf('Your score is:%.2f',score)% means to keep two decimal places for printing
fprintf('Your score is:%.2e',score)% means to keep two decimal places and print according to scientific notation
Saving and loading of variables:
>> Data=randn(10)
>> save('data.mat','Data')
>> load data.mat 或者>> load('data.mat')
The fopen function manipulates file objects
r: read mode; w: write mode; a: append mode; r+: read and write mode; w+: create mode to read and write; a+: append mode
>> fp=fopen('test.txt','a+');
>> fprintf(fp,'this is a test string.');
>> fclose(fp);
这样就创建了一个test文件,并在文件内写入了this is a test string.
logic operation
Relational operators: <, >, >=, <=, ==, ~=, true is 1, false is 0
Logical operators: and or not, &, |, ~, and, or, not
Built-in logic operation functions
any(A): Returns True if any element in the vector is non-zero, and the matrix is judged based on the column
xor: XOR
all: true when all elements are non-zero
find(A>b): Find out where the matrix is satisfying the conditional elements
>> N=[1 2 3 0;0 0 0 0;-1 -2 -3 0]
N =
1 2 3 0
0 0 0 0
-1 -2 -3 0
>> find(N>0)
ans =
1
4
7
Conditional structure
function z=f(x,y)
if x>0 && y>0
z=x+y;
elseif x>0 && y<=0
z=x+y.^2;
elseif x<=0 && y>0
z=x.^2+y;
else
z=x.^2+y.^2;
end
end
for loop structure
Taylor expansion of e^x
function y=new_exp(x)
n=100;
y=1;
for i=1:n
y=y+x^i/factorial(i);
end
end
%%factorial(i); 表示i的阶乘
while loop structure
Taylor expansion of e^x
function [n,y]=new2_exp(x)
diff=0.001;
y=1;
n=0;
while abs(exp(x)-y)>diff
n=n+1;
y=y+x^n/factorial(n);
end
end