Matlab learning 2022.7.4

I used my vacation time to pass 《MATLAB Application encyclopedia 》 And Related videos to learn matlab

  Common commands ：

clc Used to clear the contents of the command line window

clear Used to clear variables in the workspace

whos Used to display the details of variables

who Used to list the names of variables in the workspace

Use percent sign % Annotate the program

data type ：

a1 = int8(6)
a2 = int16(-20)
%int32 int64  Is a signed integer 

a3 = uint32(100)
a4 = uint64(200)
%uint8 uint16  Is an unsigned integer 

b1 = single(3.5)
% Single precision floating point 

b2 = 12
% The default is double precision floating point double

c1 = true
%logical Logical type 

c2{1,1}=100
% Is the cell array type  cell

c3='hello'
%char  Is string type 

c4.name='robin'
% Is the structure type 

[email protected]
%function_handle Is the function handle type 

value type ：

stay matlab among , The default value type is double precision floating point

a = 24
% The default variable is double precision floating point 
b1 = int8(a)

b2 = int16(a)

b3 = int32(a)

b4 = int64(a)

c = 'hello'
int8(c)
% Convert string to 8 An integer 

By function intmin() and intmax() To get the value range of integers

Rounding function of floating point numbers ：

round()、fix( towards 0 integer )、floor( Not greater than this number )、ceil( Not less than this number )

a1 = round(2.5)
a2 = round(-2.4)
a3 = round(-2.5)
b1 = fix(-3.6)
b2 = fix(-3.5)
c1 = floor(-4.2)
c2 = floor(4.9)
d1 = ceil(4.2)
d2 = ceil(-4.4)

a = 123.34
b = single(a)
c1 = double(a)
c2 = int16(a)
c3 = int32(a)

d1 = [realmin('single') realmax('single')]
d2 = [realmin('double') realmax('double')]
% By function realmin() and realmax() You can get the value range of single precision and double precision floating-point numbers 

Use complex(a,b) To create a complex number (a It is the real part ,b It is the imaginary part )

z1 = 3+4i
a1 = real(z1)
% Get the real part 
a2 = imag(z1)
% Get the imaginary part 
b1 = abs(z1)
% Get the module of the complex number 
b2 = angle(z1)
c1 = conj(z1)
% Get conjugate complex 
z2 = complex(1:3,2:4)
real(z2)
imag(z2)

Using functions format() To determine the display format of numeric type

The default display is ：format short After decimal point 4 position

format short
a = 12.3456789
format short
a
format long
a
format long e
a
format short e
a
format bank
a
format +
a
format rational
a
format short
% Restore to the system default display format 

Logical type ：

a1 = true
a2 = false
a3 = true(3,4)
a4 = false(3)
clear all
a = 3
logical(a)
b=0
logical(b)
c = [1.3 -3 0;2 0 4;0.01 9 1]
logical(c)
% Convert numeric type to logical type 

character ：

a = 'My name is zhangsan'
b = char([65 66 67 68])
c = int8('hello')
d =' Zhang '
clear all

Use function handles to call functions indirectly

% Function handle 
f1 = @cos
t = 0:pi/5:pi
f1(t)
f2 = @complex
f2(3,4)
clear all
f1 = @char
s1 = func2str(f1)
f2 = str2func(s1)
functions(f1)
isa(f1,'function_handle')
isequal(f1,f2)
clear all