命令

目的/作用

clc

清除命令窗口。

clear

从内存中删除变量。

exist

检查存在的文件或变量。

global

声明变量为全局。

help

搜索帮助主题。

lookfor

搜索帮助关键字条目。

quit

停止MATLAB。

who

列出当前变量。（很好很强大，你值得拥有）

whos

列出当前变量（长显示）。

命令

目的/作用

cd

改变当前目录。

date

显示当前日期。

delete

删除一个文件。

diary

日记文件记录开/关切换。

dir

列出当前目录中的所有文件。

load

负载工作区从一个文件中的变量。

path

显示搜索路径。

pwd

显示当前目录。

save

保存在一个文件中的工作区变量。

type

显示一个文件的??内容。

what

列出所有MATLAB文件在当前目录中。

wklread

读取.wk1电子表格文件。 

语句

描述

if ... end statement

An if ... end statement consists of a boolean expression followed by one or more statements.

if...else...end statement

An if statement can be followed by an optional else statement, which executes when the boolean expression is false.

If... elseif...elseif...else...end statements

An if statement can be followed by an (or more) optional elseif...and an else statement, which is very useful to test various condition.

nested if statements

You can use one if or elseif statement inside another if or elseif statement(s).

switch statement

A switch statement allows a variable to be tested for equality against a list of values.

nested switch statements

You can use one swicth statement inside another switch statement(s).

while 循环

一个给定的条件为真时重复语句或语句组。测试条件才执行循环体。

for 循环

执行的语句序列多次缩写管理循环变量的代码。

nested 循环

可以使用一个或多个环路内任何另一个循环。

控制语句

描述

break 语句

终止循环语句，将执行的语句紧随循环。

continue 语句

导致循环，跳过它的身体的其余部分，并立即重新再次测试前的状况。

运算符

描述

+

加法或一元加号。A + B将A和B。 A和B必须具有相同的尺寸，除非一个人是一个标量。一个标量，可以被添加到任何大小的矩阵。

-

Subtraction or unary minus. A-B subtracts B from A. A and B must have the same size, unless one is a scalar. A scalar can be subtracted from a matrix of any size.

*

Matrix multiplication. C = A*B is the linear algebraic product of the matrices A and B. More precisely,

For nonscalar A and B, the number of columns of A must equal the number of rows of B. A scalar can multiply a matrix of any size.

.*

Array multiplication. A.*B is the element-by-element product of the arrays A and B. A and B must have the same size, unless one of them is a scalar.

/

Slash or matrix right division. B/A is roughly the same as B*inv(A). More precisely, B/A = (A‘B‘)‘.

./

Array right division. A./B is the matrix with elements A(i,j)/B(i,j). A and B must have the same size, unless one of them is a scalar.

Backslash or matrix left division. If A is a square matrix, AB is roughly the same as inv(A)*B, except it is computed in a different way. If A is an n-by-n matrix and B is a column vector with n components, or a matrix with several such columns, then X = AB is the solution to the equation AX = B. A warning message is displayed if A is badly scaled or nearly singular.

.

Array left division. A.B is the matrix with elements B(i,j)/A(i,j). A and B must have the same size, unless one of them is a scalar.

^

Matrix power. X^p is X to the power p, if p is a scalar. If p is an integer, the power is computed by repeated squaring. If the integer is negative, X is inverted first. For other values of p, the calculation involves eigenvalues and eigenvectors, such that if [V,D] = eig(X), then X^p = V*D.^p/V.

.^

Array power. A.^B is the matrix with elements A(i,j) to the B(i,j) power. A and B must have the same size, unless one of them is a scalar.

‘

Matrix transpose. A‘ is the linear algebraic transpose of A. For complex matrices, this is the complex conjugate transpose.

.‘

Array transpose. A.‘ is the array transpose of A. For complex matrices, this does not involve conjugation.

函数

描述

uplus(a)

Unary plus; increments by the amount a

plus (a,b)

Plus; returns a + b

uminus(a)

Unary minus; decrements by the amount a

minus(a, b)

Minus; returns a - b

times(a, b)

Array multiply; returns a.*b

mtimes(a, b)

Matrix multiplication; returns a* b

rdivide(a, b)

Right array division; returns a ./ b

ldivide(a, b)

Left array division; returns a. b

mrdivide(A, B)

Solve systems of linear equations xA = B for x

mldivide(A, B)

Solve systems of linear equations Ax = B for x

power(a, b)

Array power; returns a.^b

mpower(a, b)

Matrix power; returns a ^ b

cumprod(A)

Cumulative product; returns an array the same size as the array A containing the cumulative product.

• If A is a vector, then cumprod(A) returns a vector containing the cumulative product of the elements of A.
• If A is a matrix, then cumprod(A) returns a matrix containing the cumulative products for each column of A.
• If A is a multidimensional array, then cumprod(A) acts along the first nonsingleton dimension.

cumprod(A, dim)

Returns the cumulative product along dimension dim.

cumsum(A)

Cumulative sum; returns an array A containing the cumulative sum.

• If A is a vector, then cumsum(A) returns a vector containing the cumulative sum of the elements of A.
• If A is a matrix, then cumsum(A) returns a matrix containing the cumulative sums for each column of A.
• If A is a multidimensional array, then cumsum(A) acts along the first nonsingleton dimension.

cumsum(A, dim)

returns the cumulative sum of the elements along dimension dim.

diff(X)

Differences and approximate derivatives; calculates differences between adjacent elements of X.

• If X is a vector, then diff(X) returns a vector, one element shorter than X, of differences between adjacent elements: [X(2)-X(1) X(3)-X(2) ... X(n)-X(n-1)]
• If X is a matrix, then diff(X) returns a matrix of row differences: [X(2:m,:)-X(1:m-1,:)]

diff(X,n)

Applies diff recursively n times, resulting in the nth difference.

diff(X,n,dim)

It is the nth difference function calculated along the dimension specified by scalar dim. If order n equals or exceeds the length of dimension dim, diff returns an empty array.

prod(A)

Product of array elements; returns the product of the array elements of A.

• If A is a vector, then prod(A) returns the product of the elements.
• If A is a nonempty matrix, then prod(A) treats the columns of A as vectors and returns a row vector of the products of each column.
• If A is an empty 0-by-0 matrix, prod(A) returns 1.
• If A is a multidimensional array, then prod(A) acts along the first nonsingleton dimension and returns an array of products. The size of this dimension reduces to 1 while the sizes of all other dimensions remain the same.

The prod function computes and returns B as single if the input, A, is single. For all other numeric and logical data types, prod computes and returns B as double

prod(A,dim)

Returns the products along dimension dim. For example, if A is a matrix, prod(A,2) is a column vector containing the products of each row.

prod(___,datatype)

multiplies in and returns an array in the class specified by datatype.

sum(A)

• Sum of array elements; returns sums along different dimensions of an array. If A is floating yiibai, that is double or single, B is accumulated natively, that is in the same class as A, and B has the same class as A. If A is not floating yiibai, B is accumulated in double and B has class double.
• If A is a vector, sum(A) returns the sum of the elements.
• If A is a matrix, sum(A) treats the columns of A as vectors, returning a row vector of the sums of each column.
• If A is a multidimensional array, sum(A) treats the values along the first non-singleton dimension as vectors, returning an array of row vectors.

sum(A,dim)

Sums along the dimension of A specified by scalar dim.

sum(..., ‘double‘)

sum(..., dim,‘double‘)

Perform additions in double-precision and return an answer of type double, even if A has data type single or an integer data type. This is the default for integer data types.

sum(..., ‘native‘)

sum(..., dim,‘native‘)

Perform additions in the native data type of A and return an answer of the same data type. This is the default for single and double.

ceil(A)

Round toward positive infinity; rounds the elements of A to the nearest integers greater than or equal to A.

fix(A)

Round toward zero

floor(A)

Round toward negative infinity; rounds the elements of A to the nearest integers less than or equal to A.

idivide(a, b)

idivide(a, b,‘fix‘)

Integer division with rounding option; is the same as a./b except that fractional quotients are rounded toward zero to the nearest integers.

idivide(a, b, ‘round‘)

Fractional quotients are rounded to the nearest integers.

idivide(A, B, ‘floor‘)

Fractional quotients are rounded toward negative infinity to the nearest integers.

idivide(A, B, ‘ceil‘)

Fractional quotients are rounded toward infinity to the nearest integers.

mod (X,Y)

Modulus after division; returns X - n.*Y where n = floor(X./Y). If Y is not an integer and the quotient X./Y is within roundoff error of an integer, then n is that integer. The inputs X and Y must be real arrays of the same size, or real scalars (provided Y ~=0).

Please note:

• mod(X,0) is X
• mod(X,X) is 0
• mod(X,Y) for X~=Y and Y~=0 has the same sign as Y

rem (X,Y)

Remainder after division; returns X - n.*Y where n = fix(X./Y). If Y is not an integer and the quotient X./Y is within roundoff error of an integer, then n is that integer. The inputs X and Y must be real arrays of the same size, or real scalars(provided Y ~=0).

Please note that:

• rem(X,0) is NaN
• rem(X,X) for X~=0 is 0
• rem(X,Y) for X~=Y and Y~=0 has the same sign as X.

round(X)

Round to nearest integer; rounds the elements of X to the nearest integers. Positive elements with a fractional part of 0.5 round up to the nearest positive integer. Negative elements with a fractional part of -0.5 round down to the nearest negative integer.

函数

描述

eq(a, b)

Tests whether a is equal to b

ge(a, b)

Tests whether a is greater than or equal to b

gt(a, b)

Tests whether a is greater than b

le(a, b)

Tests whether a is less than or equal to b

lt(a, b)

Tests whether a is less than b

ne(a, b)

Tests whether a is not equal to b

isequal

Tests arrays for equality

isequaln

Tests arrays for equality, treating NaN values as equal

运算符

描述

< 

Less than

<=

Less than or equal to

> 

Greater than

>=

Greater than or equal to

==

Equal to

~=

Not equal to

函数

描述

and(A, B)

Finds logical AND of array or scalar inputs; performs a logical AND of all input arrays A, B, etc. and returns an array containing elements set to either logical 1 (true) or logical 0 (false). An element of the output array is set to 1 if all input arrays contain a nonzero element at that same array location. Otherwise, that element is set to 0.

not(A)

Finds logical NOT of array or scalar input; performs a logical NOT of input array A and returns an array containing elements set to either logical 1 (true) or logical 0 (false). An element of the output array is set to 1 if the input array contains a zero value element at that same array location. Otherwise, that element is set to 0.

or(A, B)

Finds logical OR of array or scalar inputs; performs a logical OR of all input arrays A, B, etc. and returns an array containing elements set to either logical 1 (true) or logical 0 (false). An element of the output array is set to 1 if any input arrays contain a nonzero element at that same array location. Otherwise, that element is set to 0.

xor(A, B)

Logical exclusive-OR; performs an exclusive OR operation on the corresponding elements of arrays A and B. The resulting element C(i,j,...) is logical true (1) if A(i,j,...) or B(i,j,...), but not both, is nonzero.

all(A)

Determine if all array elements of array A are nonzero or true.

• If A is a vector, all(A) returns logical 1 (true) if all the elements are nonzero and returns logical 0 (false) if one or more elements are zero.
• If A is a nonempty matrix, all(A) treats the columns of A as vectors, returning a row vector of logical 1‘s and 0‘s.
• If A is an empty 0-by-0 matrix, all(A) returns logical 1 (true).
• If A is a multidimensional array, all(A) acts along the first nonsingleton dimension and returns an array of logical values. The size of this dimension reduces to 1 while the sizes of all other dimensions remain the same.

all(A, dim)

Tests along the dimension of A specified by scalar dim.

any(A)

Determine if any array elements are nonzero; tests whether any of the elements along various dimensions of an array is a nonzero number or is logical 1 (true). The any function ignores entries that are NaN (Not a Number).

• If A is a vector, any(A) returns logical 1 (true) if any of the elements of A is a nonzero number or is logical 1 (true), and returns logical 0 (false) if all the elements are zero.
• If A is a nonempty matrix, any(A) treats the columns of A as vectors, returning a row vector of logical 1‘s and 0‘s.
• If A is an empty 0-by-0 matrix, any(A) returns logical 0 (false).
• If A is a multidimensional array, any(A) acts along the first nonsingleton dimension and returns an array of logical values. The size of this dimension reduces to 1 while the sizes of all other dimensions remain the same.

any(A,dim)

Tests along the dimension of A specified by scalar dim.

false

Logical 0 (false)

false(n)

is an n-by-n matrix of logical zeros

false(m, n)

is an m-by-n matrix of logical zeros.

false(m, n, p, ...)

is an m-by-n-by-p-by-... array of logical zeros.

false(size(A))

is an array of logical zeros that is the same size as array A.

false(...,‘like‘,p)

is an array of logical zeros of the same data type and sparsity as the logical array p.

ind = find(X)

Find indices and values of nonzero elements; locates all nonzero elements of array X, and returns the linear indices of those elements in a vector. If X is a row vector, then the returned vector is a row vector; otherwise, it returns a column vector. If X contains no nonzero elements or is an empty array, then an empty array is returned.

ind = find(X, k)

ind = find(X, k, ‘first‘)

Returns at most the first k indices corresponding to the nonzero entries of X. k must be a positive integer, but it can be of any numeric data type.

ind = find(X, k, ‘last‘)

returns at most the last k indices corresponding to the nonzero entries of X.

[row,col] = find(X, ...)

Returns the row and column indices of the nonzero entries in the matrix X. This syntax is especially useful when working with sparse matrices. If X is an N-dimensional array with N > 2, col contains linear indices for the columns.

[row,col,v] = find(X, ...)

Returns a column or row vector v of the nonzero entries in X, as well as row and column indices. If X is a logical expression, then v is a logical array. Output v contains the non-zero elements of the logical array obtained by evaluating the expression X.

islogical(A)

Determine if input is logical array; returns true if A is a logical array and false otherwise. It also returns true if A is an instance of a class that is derived from the logical class.

logical(A)

Convert numeric values to logical; returns an array that can be used for logical indexing or logical tests.

true

Logical 1 (true)

true(n)

is an n-by-n matrix of logical ones.

true(m, n)

is an m-by-n matrix of logical ones.

true(m, n, p, ...)

is an m-by-n-by-p-by-... array of logical ones.

true(size(A))

is an array of logical ones that is the same size as array A.

true(...,‘like‘, p)

is an array of logical ones of the same data type and sparsity as the logical array p.

p

q

p & q

p | q

p ^ q

0

0

0

0

0

0

1

0

1

1

1

1

1

1

0

1

0

0

1

1

函数

目的/作用

bitand(a, b)

Bit-wise AND of integers a and b

bitcmp(a)

Bit-wise complement of a

bitget(a,pos)

Get bit at specified position pos, in the integer array a

bitor(a, b)

Bit-wise OR of integers a and b

bitset(a, pos)

Set bit at specific location pos of a

bitshift(a, k)

Returns a shifted to the left by k bits, equivalent to multiplying by 2^k. Negative values of k correspond to shifting bits right or dividing by 2^|k| and rounding to the nearest integer towards negative infinite. Any overflow bits are truncated.

bitxor(a, b)

Bit-wise XOR of integers a and b

swapbytes

Swap byte ordering

函数

描述

intersect(A,B)

Set intersection of two arrays; returns the values common to both A and B. The values returned are in sorted order.

intersect(A,B,‘rows‘)

Treats each row of A and each row of B as single entities and returns the rows common to both A and B. The rows of the returned matrix are in sorted order.

ismember(A,B)

Returns an array the same size as A, containing 1 (true) where the elements of A are found in B. Elsewhere, it returns 0 (false).

ismember(A,B,‘rows‘)

Treats each row of A and each row of B as single entities and returns a vector containing 1 (true) where the rows of matrix A are also rows of B. Elsewhere, it returns 0 (false).

issorted(A)

Returns logical 1 (true) if the elements of A are in sorted order and logical 0 (false) otherwise. Input A can be a vector or an N-by-1 or 1-by-N cell array of strings. A is considered to be sorted if A and the output of sort(A) are equal.

issorted(A, ‘rows‘)

Returns logical 1 (true) if the rows of two-dimensional matrix A are in sorted order, and logical 0 (false) otherwise. Matrix A is considered to be sorted if A and the output of sortrows(A) are equal.

setdiff(A,B)

Set difference of two arrays; returns the values in A that are not in B. The values in the returned array are in sorted order.

setdiff(A,B,‘rows‘)

Treats each row of A and each row of B as single entities and returns the rows from A that are not in B. The rows of the returned matrix are in sorted order.

The ‘rows‘ option does not support cell arrays.

setxor

Set exclusive OR of two arrays

union

Set union of two arrays

unique

Unique values in array

函数

描述

intersect(A,B)

Set intersection of two arrays; returns the values common to both A and B. The values returned are in sorted order.

intersect(A,B,‘rows‘)

Treats each row of A and each row of B as single entities and returns the rows common to both A and B. The rows of the returned matrix are in sorted order.

ismember(A,B)

Returns an array the same size as A, containing 1 (true) where the elements of A are found in B. Elsewhere, it returns 0 (false).

ismember(A,B,‘rows‘)

Treats each row of A and each row of B as single entities and returns a vector containing 1 (true) where the rows of matrix A are also rows of B. Elsewhere, it returns 0 (false).

issorted(A)

Returns logical 1 (true) if the elements of A are in sorted order, and logical 0 (false) otherwise. Input A can be a vector or an N-by-1 or 1-by-N cell array of strings. A is considered to be sorted if A and the output of sort(A) are equal.

issorted(A, ‘rows‘)

Returns logical 1 (true) if the rows of two-dimensional matrix A are in sorted order, and logical 0 (false) otherwise. Matrix A is considered to be sorted if A and the output of sortrows(A) are equal.

setdiff(A,B)

Set difference of two arrays; returns the values in A that are not in B. The values in the returned array are in sorted order.

setdiff(A,B,‘rows‘)

Treats each row of A and each row of B as single entities and returns the rows from A that are not in B. The rows of the returned matrix are in sorted order.

The ‘rows‘ option does not support cell arrays.

setxor

Set exclusive OR of two arrays

union

Set union of two arrays

unique

Unique values in array

命令

作用/目的

disp

显示一个数组或字符串的内容。

fscanf

阅读从文件格式的数据。

format

控制屏幕显示的格式。

fprintf

执行格式化写入到屏幕或文件。

input

显示提示并等待输入。

;

禁止显示网版印刷

格式代码

目的/作用

%s

Format as a string.

%d

Format as an integer.

%f

Format as a floating yiibai value.

%e

Format as a floating yiibai value in scientific notation.

%g

Format in the most compact form: %f or %e.

Insert a new line in the output string.

Insert a tab in the output string.

Format函数

最多可显示

format short

Four decimal digits (default).

format long

16 decimal digits.

format short e

Five digits plus exponent.

format long e

16 digits plus exponents.

format bank

Two decimal digits.

format +

Positive, negative, or zero.

format rat

Rational approximation.

format compact

Suppresses some line feeds.

format loose

Resets to less compact display mode.

命令

作用/目的

cat

Concatenates arrays.连接数组

find

Finds indices of nonzero elements.

length

Computes number of elements.

linspace

Creates regularly spaced vector.

logspace

Creates logarithmically spaced vector.

max

Returns largest element.

min

Returns smallest element.

prod

Product of each column.

reshape

Changes size.

size

Computes array size.

sort

Sorts each column.

sum

Sums each column.

eye

Creates an identity matrix. 创建单位矩阵

ones

Creates an array of ones. 创建一个1的数组

zeros

Creates an array of zeros. 创建一个0数组

cross

Computes matrix cross products.计算矩阵交叉积

dot

Computes matrix dot products. 点积

det

Computes determinant of an array.计算行列式

inv

Computes inverse of a matrix.计算行列式的逆

pinv

Computes pseudoinverse of a matrix.计算行列式的违逆

rank

Computes rank of a matrix.计算行列式的秩

rref

Computes reduced row echelon form.

cell

Creates cell array.

celldisp

Displays cell array.

cellplot

Displays graphical representation of cell array.

num2cell

Converts numeric array to cell array.

deal

Matches input and output lists.

iscell

Identifies cell array.

命令

作用/目的

axis

Sets axis limits.

fplot

Intelligent plotting of functions.

grid

Displays gridlines.

plot

Generates xy plot.

print

Prints plot or saves plot to a file.

title

Puts text at top of plot.

xlabel

Adds text label to x-axis.

ylabel

Adds text label to y-axis.

axes

Creates axes objects.

close

Closes the current plot.

close all

Closes all plots.

figure

Opens a new figure window.

gtext

Enables label placement by mouse.

hold

Freezes current plot.

legend

Legend placement by mouse.

refresh

Redraws current figure window.

set

Specifies properties of objects such as axes.

subplot

Creates plots in subwindows.

text

Places string in figure.

bar

Creates bar chart.

loglog

Creates log-log plot.

polar

Creates polar plot.

semilogx

Creates semilog plot. (logarithmic abscissa).

semilogy

Creates semilog plot. (logarithmic ordinate).

stairs

Creates stairs plot.

stem

Creates stem plot.