MATLAB数据类型

MATLAB 并不需要任何类型的声明或维度报表。 MATLAB 每当遇到一个新的变量名称，创建变量，并分配适当的内存空间。

如果变量已经存在，则MATLAB替换以新的内容的原始内容，并分配新的存储空间，在必要的情况下。

例如，

Total=42

上述语句创建了一个名为“Total” 的 1-1 矩阵存储值42。

MATLAB中可用的数据类型

MATLAB 提供15个基本数据类型。每种数据类型的数据存储在矩阵或阵列的形式。这个矩阵的大小或阵列是一个最低 0-0，这可以长大为任何规模大小的矩阵或数组。

下表显示了在 MATLAB 中最常用的数据类型：

数据类型

描述

int8

8-bit signed integer

uint8

8-bit unsigned integer

int16

16-bit signed integer

uint16

16-bit unsigned integer

int32

32-bit signed integer

uint32

32-bit unsigned integer

int64

64-bit signed integer

uint64

64-bit unsigned integer

single

single precision numerical data

double

double precision numerical data

logical

logical values of 1 or 0, represent true and false respectively

char

character data (strings are stored as vector of characters)

cell array

array of indexed cells, each capable of storing an array of a different dimension and data type

structure

C-like structures, each structure having named fields capable of storing an array of a different dimension and data type

function handle

yiibaier to a function

user classes

objects constructed from a user-defined class

java classes

objects constructed from a Java class

例子

创建一个脚本文件，用下面的代码：

str='Hello World!'n=2345d=double(n)un=uint32(789.50)rn=5678.92347c=int32(rn)

上面的代码编译和执行时，它会产生以下结果：

str =

Hello World!

n =

2345

d =

2345

un =

790

rn =

5.6789e+03

c =

5679

数据类型转换

MATLAB 提供各种函数，用于从一种数据类型转换到另一种。下表显示的数据类型转换函数：

函数

目的/作用

char

Convert to character array (string)

int2str

Convert integer data to string

mat2str

Convert matrix to string

num2str

Convert number to string

str2double

Convert string to double-precision value

str2num

Convert string to number

native2unicode

Convert numeric bytes to Unicode characters

unicode2native

Convert Unicode characters to numeric bytes

base2dec

Convert base N number string to decimal number

bin2dec

Convert binary number string to decimal number

dec2base

Convert decimal to base N number in string

dec2bin

Convert decimal to binary number in string

dec2hex

Convert decimal to hexadecimal number in string

hex2dec

Convert hexadecimal number string to decimal number

hex2num

Convert hexadecimal number string to double-precision number

num2hex

Convert singles and doubles to IEEE hexadecimal strings

cell2mat

Convert cell array to numeric array

cell2struct

Convert cell array to structure array

cellstr

Create cell array of strings from character array

mat2cell

Convert array to cell array with potentially different sized cells

num2cell

Convert array to cell array with consistently sized cells

struct2cell

Convert structure to cell array

测定的数据类型

MATLAB 提供各种函数标识数据类型的变量。

下表提供了确定一个变量的数据类型的函数：

函数

目的/作用

is

Detect state

isa

Determine if input is object of specified class

iscell

Determine whether input is cell array

iscellstr

Determine whether input is cell array of strings

ischar

Determine whether item is character array

isfield

Determine whether input is structure array field

isfloat

Determine if input is floating-yiibai array

ishghandle

True for Handle Graphics object handles

isinteger

Determine if input is integer array

isjava

Determine if input is Java object

islogical

Determine if input is logical array

isnumeric

Determine if input is numeric array

isobject

Determine if input is MATLAB object

isreal

Check if input is real array

isscalar

Determine whether input is scalar

isstr

Determine whether input is character array

isstruct

Determine whether input is structure array

isvector

Determine whether input is vector

class

Determine class of object

validateattributes

Check validity of array

whos

List variables in workspace, with sizes and types

例子

创建一个脚本文件，用下面的代码：

x=3isinteger(x)isfloat(x)isvector(x)isscalar(x)isnumeric(x)x=23.54isinteger(x)isfloat(x)isvector(x)isscalar(x)isnumeric(x)x=[123]isinteger(x)isfloat(x)isvector(x)isscalar(x)x='Hello'isinteger(x)isfloat(x)isvector(x)isscalar(x)isnumeric(x)

当运行该文件，它会产生以下结果：

x =

3

ans =

0

ans =

1

ans =

1

ans =

1

ans =

1

x =

23.5400

ans =

0

ans =

1

ans =

1

ans =

1

ans =

1

x =

1 2 3

ans =

0

ans =

1

ans =

1

ans =

0

x =

Hello

ans =

0

ans =

0

ans =

1

ans =

0

ans =

0