Basic mathematical operation symbols

Symbol	function	Symbol	function
+	addition	-	subtraction
*	Matrix multiplication	.*	Multiplication, dot multiplication, that is, array multiplication
/	Right division	./	Right division of array
\	be demoted	'\'.	Array left division (there is no single quotation mark here)
^	Power	.^	Array power
'	Matrix conjugate reprint	.'	Matrix transpose

Simple example of basic operation

>>%Definition matrix A Sum matrix B
>>A=round(rand(3)*10)
A=
	9	4	4
	3	5	7
	4	9	1
>>B=magic(3)
B=
	8	1	6
	3	5	7
	4	9	2
>>%Cross multiplication and dot multiplication of matrices
>>C1=A*B
C1=
	100	65	90
	119	133	123
	47	56	77
>>C2=A.*B
C2=
	72	4	24
	21	45	63
	8   81	2
>>%Left division and right division of matrices
>>D1=A./B
D1=
	1.1250	  4.0000    0.6667
	2.3333	  1.8000    1.2857
	0.5000   1.0000    0.5000
>>D2=A.\B
>D2=
	0.8889   0.2500  1.5000
	0.4286   0.5556   0.7778
	2.0000   1.0000   2.0000
>>%Matrix power 
>>E1=A.^2
E1=
	81	16	16
	49	81	81
	4	81	1
>>E2=A^2
E2=
	117	108	76
	144	190	118
	83	98	90

As can be seen from the example, no matter which operation method (multiplication, division and power), it is marked with "." The operation mode of represents the operation on the elements of the matrix. For a matrix, the right division of a matrix is a division in a general sense, while the left Division has a symmetrical meaning, that is, A./B=B.\A.

Common punctuation in the command line

Symbol	name	Function and significance
'space'	Space	Separator between input quantities (these spaces between variables will be ignored in the command window); Enter the separator between array elements
，	comma	To display the separation between the calculation results and other commands; Separator between input quantities or between array elements
.	spot	In numerical calculation, it can be used as a decimal point; In the process of array operation, it can be used as the indicator of element operation
；	semicolon	At the end of the command line, it means that the calculation result will not be displayed after the calculation; Or as a separator between array rows when entering an array
:	colon	When generating a one-dimensional array, it can be used as a separator; All sequences composed of all elements used for single subscript reference; Separator during loop operation
%	Percent sign	It is located at the beginning of the command line, indicating that the line is a comment line, which increases the readability of the input or deformed file. All contents after the percent sign are comment contents, which are not compiled and displayed in the command window
''	Single quote pair	Used to define a string
()	Parentheses	Change the priority order in the operation process; Used in function calls; Index as array
[]	square brackets	Definition matrix
{}	Curly bracket	Define cell array, special character parentheses in graphics
_	Underline	Hyphens used when defining variables, functions, or files; The leading symbol of the subscript in a graph
...	Continuation number	When the command in the input command window is long, you can enter more than 3 point numbers on the first line and continue to enter the command on the next line to complete the input and execution of the long command
@	"At" No	Put it in front of the function name to form a function handle; As the leading character of an anonymous function
!	exclamatory mark	Call operating system operation

Common operations and editing commands in the command window

command	Function and significance	command	Function and significance
cd	Show or change working directory	pack	Defragment memory
clc	Clear command window	path	Show search directory
clear	Clear variables in workspace	quit	Exit MATLAB
clf	Clear graphics window	save	Save memory variables
disary	Log file naming	type	Show file contents
dir	Displays the files in the current directory	what	List MATLAB files in the directory
disp	Displays the contents of a variable or text	which	Locate the path to the MATLAB file
echo	Command window information display switch	who	Lists the variables for the workspace
hold	Drawing hold command	whos	Detailed list of workspace variables
load	Loads variables in the specified file

MATLAB operation command demonstration

>>who
Your variables are:
A	B	C1	C2	D1	D2	E1	E2
>>whos
	Name	Sive	Byte	Class
	A		3*3		  72	double arry
	B		3*3		  72	double arry
	C1		3*3		  72	double arry
	C2		3*3		  72	double arry
	D1		3*3		  72	double arry
	D2		3*3		  72	double arry
	E1		3*3		  72	double arry
	E2		3*3		  72	double arry
Grand total is 72 elements uisng 576 bytes
>>what
M-files in the current disrectory d:\Program Files\MATLAB71\work
cplxmap    intexp3    m4simu13    optfun    updown1
flow1		m4_simu14	mysource	tmps	updown2
MEX-files in the current directory d:\Program File\MATLAB71\work
fact		myclac
MDL-files in the current directory d:\Program File\MATLAB71\work
signa9		simu3
signa10		simu4
simu1		simu5
simu11		simu6
simu12		simu7
simu13		simu8
simu13_state_space		simu_15
simu14_transfer_function simu_continuous0
simu14_nonliner 	simu_continuousl
simu2
>>clear

Display of command window

Format command	meaning
format short	Including 4 significant digits after the decimal point, and no more than 7 significant digits at most; If the value is greater than 1000, it is expressed according to the scientific counting method
format long	Represented by 15 digits
format short e	5-digit scientific counting method
format long e	15 bit scientific calculation method
foramt short g	Automatically select the best numerical representation from format short and format short e
format long g	Automatically select the best numerical representation from format long and format long e
format rat	It is expressed by approximate rational numbers
format hex	Hexadecimal representation
format +	It is used for +, - and spaces to represent positive, negative and zero respectively. Imaginary numbers in complex numbers are not represented
format bank	Financial representation, yuan, angle, grade
format compart	There are no spaces between display variables
format loose	Space between display variables