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TA的每日心情 | 慵懒 2020-7-12 09:52 |
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签到天数: 116 天 [LV.6]常住居民II 管理员
 群组: 2018教师培训(呼和浩 群组: 2017-05-04 量化投资实 群组: 2017“草原杯”夏令营 群组: 2018美赛冲刺培训 群组: 2017 田老师国赛冲刺课 |
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。
]6 z# r' v2 {0 h) _
; V2 [# q& l- s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。
% Q9 T a/ x6 B c# h l, e/ N* H, e- ?( b
例如,% D' |7 Y( |+ Q2 `( L
7 V* u4 l" c4 V# U; K1 nTotal = 42# G2 j3 f" a; v" ]2 y
上述语句创建了一个名为“Total” 的 1-1 矩阵存储值42。% @; v9 O. p0 u+ q0 i6 J% Y5 i
/ x1 x& u/ H( `; ]9 \9 c& RMATLAB中可用的数据类型) S2 b( F7 t9 j5 f* P
% N; Z- E( X( C3 @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。
$ R* T) `: ~- Z- Y# {( v
4 [/ _# \3 x) D3 a) W下表显示了在 MATLAB 中最常用的数据类型:
* n5 A" T2 a3 D9 g( d( }. Y
3 B, P- j. _6 s' o; M& g' {数据类型 描述
7 n/ v& l; l5 u& }int8 8-bit signed integer
3 |' ^& u/ o2 Q w* ^: S( Wuint8 8-bit unsigned integer
+ f4 B7 a1 }3 g. }+ Tint16 16-bit signed integer; E, Z. `- J% l4 s' S- E; s
uint16 16-bit unsigned integer1 x" D3 `7 e. O: T9 Z4 ^
int32 32-bit signed integer
. ]2 j' g v% O; F+ ~7 Juint32 32-bit unsigned integer
$ q3 p1 e3 }# y5 j5 i) qint64 64-bit signed integer
/ G5 Y# n6 y: O8 l7 Fuint64 64-bit unsigned integer
# l" x0 h% Z& c1 R2 L' ?; i% Rsingle single precision numerical data* e: n2 d! \: ^, U
double double precision numerical data: |2 I" |6 w& a
logical logical values of 1 or 0, represent true and false respectively
. |' i/ D" R$ Z4 w- Qchar character data (strings are stored as vector of characters)
+ I0 o& |7 j5 `+ Lcell array array of indexed cells, each capable of storing an array of a different dimension and data type J2 A7 L" `, o8 R+ d. |- a7 \
structure C-like structures, each structure having named fields capable of storing an array of a different dimension and data type) K* Q5 ~( V; \- e8 G2 Y! [
function handle yiibaier to a function
8 c# Q- `' N( f7 j8 e+ H( h0 t6 B' Fuser classes objects constructed from a user-defined class7 x% i/ ^ [3 p7 {4 u. {
java classes objects constructed from a Java class* D" }1 C1 [! n6 a- K X3 L
例子7 W* T7 S+ h- _$ o
( s" X$ j8 O4 B4 p! g% r
创建一个脚本文件,用下面的代码:: f0 j: t9 ]. u. A1 K
- O/ U Q3 v( G- B$ N1 l& H" t
str = 'Hello World!'
% N) E) f- Y e$ p e8 w* ]5 [) qn = 23452 C0 ~: S9 J+ L: b
d = double(n)) G7 k9 h- M' N r0 j2 Y
un = uint32(789.50)9 P3 r _# R) ~2 ?
rn = 5678.92347# t) C7 z1 O7 O2 N+ r
c = int32(rn)9 w9 m( G9 t' k. r
上面的代码编译和执行时,它会产生以下结果:) @$ [8 F& H' k7 ` w ?
U& I2 h/ p7 x7 [str =
, C N! D1 W# r* z. WHello World!
/ b3 ~, ]. N/ ~n =
+ ]8 f$ d( s6 s3 t$ j' [ 2345
. Q1 _# G/ Z3 e& Z" ^- id =! S; P7 Y; Z" U# B* x4 t# S
2345/ V$ z6 O- c" P! g" p: i6 M
un =; t. H1 D0 n$ t' h* n
790
' H( z8 d; U8 R! r: H9 lrn =# [/ D2 ?6 [3 k. S+ {8 v
5.6789e+03
$ M- I \3 k. t. gc =
+ W+ r& R Q( x1 n 5679
) }4 u6 l$ @0 l) o% d# j数据类型转换4 q5 S8 ]+ w7 j. e% v6 r+ M" t; [) b
! W; F) }( U( k' Z9 i6 {3 n6 p1 `9 tMATLAB 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:/ Y4 y9 B$ k! w a( c, s
$ Q$ b# b" ? R2 z: [函数 目的/作用3 \6 P* _, r/ D! T6 L
char Convert to character array (string)# f" W/ @0 k! H5 S# f
int2str Convert integer data to string6 _2 q5 Z! S: n/ A% i1 ^
mat2str Convert matrix to string
R( p. U4 y8 |num2str Convert number to string, f! x1 q% s3 v3 a
str2double Convert string to double-precision value
Z2 q. T6 z. `str2num Convert string to number
9 n" z) Q7 m R. G! t( i$ mnative2unicode Convert numeric bytes to Unicode characters5 w; |) v7 s* L& ~7 Y" e
unicode2native Convert Unicode characters to numeric bytes( i/ a& w* n' l. h) @9 b* H, H
base2dec Convert base N number string to decimal number1 A% U# F7 b% K3 i& g- X
bin2dec Convert binary number string to decimal number) D. n* `/ F) C# G- e+ L
dec2base Convert decimal to base N number in string
$ A5 D$ E& l7 `dec2bin Convert decimal to binary number in string. t/ ?2 l' ~ F6 _, L2 B
dec2hex Convert decimal to hexadecimal number in string
5 U* j6 {. u5 f+ P% mhex2dec Convert hexadecimal number string to decimal number
1 c7 E7 i/ M3 C2 g+ ?0 K& \& ?hex2num Convert hexadecimal number string to double-precision number
4 X% M1 k# r( Z1 d! snum2hex Convert singles and doubles to IEEE hexadecimal strings
* g% `" S/ f3 m# g, ucell2mat Convert cell array to numeric array
/ b+ l2 M% l" \! tcell2struct Convert cell array to structure array
' E3 _& n/ t& r Y. w. q& g" }- b( J% zcellstr Create cell array of strings from character array
# x# J- `" r% m7 t& B% x. rmat2cell Convert array to cell array with potentially different sized cells
9 ?: E" D; l1 M0 inum2cell Convert array to cell array with consistently sized cells$ x- o6 P0 x, w2 ^9 `
struct2cell Convert structure to cell array. o% e/ w3 q+ ?
测定的数据类型' h5 d: e7 Y( P3 M# B* P
1 i- a2 w4 f. A+ T5 ^* U8 B6 t3 wMATLAB 提供各种函数标识数据类型的变量。
( d1 u+ F5 L3 J- Z) i+ t. Y6 k4 T# K+ N' h1 f$ Z, }
下表提供了确定一个变量的数据类型的函数:
# q: H+ `& s8 {3 a6 E( [' w1 R/ d1 N
函数 目的/作用- @& q' \) Y6 z9 I9 H! X: i
is Detect state
9 e6 B K9 @ b" a2 L% e4 A7 @& Disa Determine if input is object of specified class
5 ?+ h- L" u) @) hiscell Determine whether input is cell array
3 |8 q$ o* v, W. q2 Y" Wiscellstr Determine whether input is cell array of strings
' ?" G \' ~$ S" G% _ischar Determine whether item is character array
+ }9 z" L* S4 w9 h3 E8 J% oisfield Determine whether input is structure array field
4 `4 e/ U3 H; |/ A+ \isfloat Determine if input is floating-yiibai array" y/ o; D9 v. `) \1 ~/ j! X! }3 G
ishghandle True for Handle Graphics object handles6 W% `6 E6 ^2 b" g
isinteger Determine if input is integer array1 \4 f: T) G, F% s( r
isjava Determine if input is Java object7 g9 m+ h+ g G6 W: T4 @8 H ^
islogical Determine if input is logical array
, B' c) t6 ^5 r- u1 [& qisnumeric Determine if input is numeric array4 E; }, [; x! a. M$ X: Z
isobject Determine if input is MATLAB object& Q6 K# V9 s$ J" |9 Q) B
isreal Check if input is real array
1 P) U' l0 G( \, M3 Fisscalar Determine whether input is scalar
1 `" z# S8 C3 O( S' n/ pisstr Determine whether input is character array
- h1 i' @4 L3 W/ Risstruct Determine whether input is structure array
+ n# p' a% n& i: hisvector Determine whether input is vector
8 D9 |* f \5 u; V2 G7 jclass Determine class of object
) v4 d- v0 l2 W3 k0 `6 O" \validateattributes Check validity of array- O$ ]7 V+ {$ @2 Y
whos List variables in workspace, with sizes and types
8 M0 [" e7 r+ v5 r( o- ~例子
% _1 \+ q# Y) R& ]
5 |, Y# d9 V4 e5 h7 L) M4 ]创建一个脚本文件,用下面的代码:
( c+ p) H- R3 k3 m! H0 F, }
9 a1 y* t: ]+ Zx = 3
9 e& N0 |& Q# m7 m* D4 i5 qisinteger(x)
9 P& N6 f* a3 G2 a5 `4 N8 Q1 Jisfloat(x), @( X5 Y) J$ m) b g1 ~
isvector(x)
m, G' t0 i" N9 U, _% v2 |isscalar(x)" s' W& {# o7 }4 R- u
isnumeric(x)3 ]7 i% H" F0 e- X
$ Y1 e! ^7 C; Y3 T/ z- A% Ax = 23.54$ j* | h; G5 t$ j0 X7 x# \1 ~
isinteger(x)
$ ^- ?% d0 l! Sisfloat(x)
7 ~! ~% N6 v5 W. `8 W+ c% t" aisvector(x)
$ K8 r. y2 }1 V* }isscalar(x)6 E2 U- `" f) }1 w) ~) W+ j: @
isnumeric(x)7 Z1 W& l8 b9 h7 x
. m, f4 p4 S4 i! b! {5 E
x = [1 2 3]; [* @7 q7 r& J! w7 X
isinteger(x)
, b7 D9 M2 ?" }3 {' v! hisfloat(x)
. d1 J" I. y* Q, f" C4 f2 eisvector(x)
2 h3 P" B9 @- f) E& \9 E* gisscalar(x)
/ D; H) @ z/ Q( l& g+ u
/ E8 o5 X0 H% i5 {9 Y4 Y5 ]) dx = 'Hello'
2 }$ ]' D% X1 O/ d& a; I& v) {isinteger(x)2 G; X, `+ d3 @/ A
isfloat(x)$ K1 I2 t+ u* L
isvector(x)
$ X3 b' L$ d% W: U8 O8 K! Q( Eisscalar(x)3 n* k+ Y( Z. Z" b
isnumeric(x)
+ A/ G+ r* U7 ?+ g( i2 n# o8 s当运行该文件,它会产生以下结果:
+ X8 |3 r: ~. a$ s0 o
; v( t3 n s* b2 s( nx =% y; U# a1 |: t# F- H" s; O# M
3( x* p: ?' B' U) Z+ j1 u- i8 h
ans =. T% {6 t) g" W- A; m# g) t4 a
0
( X0 M. r- z+ b( D1 {4 Hans =
# \. f4 J/ V: B' m5 W _9 w 14 `- l+ t; E; Q6 j- m' F6 O
ans =; o8 A8 u1 b( v
1! @4 W9 w; u' {% n" b/ E6 X) ^$ ]
ans =
8 z7 q$ i0 S/ q2 X+ ^3 C8 ~+ b 18 v6 y; }+ l, c% Z' G# H: Y
ans =9 g B! l* _$ `& N
1
) @) S7 V$ L7 s! v" Z5 e" N6 Dx =8 ^# f* G8 D3 I4 T! {! J6 f! U
23.5400
& s# j) Z: b% ^3 ~ans =
+ C( s' u; g! G9 O% M1 c$ ?- h( _ 0+ Q: z5 K- w3 J: U
ans =* y, u* S% u' z2 U
1
8 _( q V+ F+ \5 F) ^* W+ ^6 J* cans =
% \/ ^* u! E. V$ ~- m6 O" w9 y 1
. f! C, |& M) h0 T" G S/ b. [) [- oans =1 _* d& y0 G2 R+ [3 e/ X) `1 B
1! c& s1 z: G6 W' x- ^
ans =
/ [$ z |& _5 q/ H. A4 Z 1
4 V% ^5 X* Y& L; z- m7 D. b) px =7 y* Z- Y2 U2 r: D. F
1 2 3
w4 \& n/ k' Gans =
" X- S- \$ r) ~* j7 B! {& g7 S `; M% s 0
( }4 v- {" F5 O2 n0 b, r2 Hans =
9 e0 f; b; @. a- r- @' } 1
' K9 X# Z7 F3 G% W2 _5 C5 w$ oans = B' H* I1 K8 ~: n
1) u- J: P* `: J) i; ]# [0 g
ans =
7 G- K1 W% |: P! X0 g- L& X* l 0
1 L, ~- S3 K, h$ [* h( Rx =7 ^. b- i; I* R# a
Hello
1 e7 |8 d2 f/ x7 z+ g1 V$ ^+ Vans =
. e0 C& |$ [9 t$ d K# L# i9 G 0
6 C# Z0 S; s6 W6 i# cans =- b/ l0 Y4 T- P* ?, v1 k
0, F0 T3 P9 R8 y- L9 c- L
ans =% F% v7 i3 M8 p. h
1! B4 A8 m+ \1 l: K; G4 k& _% D+ W
ans =! F* U8 Z- l' X3 t8 p
0
: R8 x# G, U, f+ J, Q$ c& p& @8 Oans =6 i5 U8 ^! V: M3 Q' P% ]7 z- H
0
7 n: d" c7 e: [+ Q' m1 X: \% v: l* L$ |9 R4 Q- n/ T6 B) v
————————————————& n0 K1 i+ S1 Q( l2 O! \
版权声明:本文为CSDN博主「Phil__ming」的原创文章。' E2 q, ]( J( w
原文链接:https://blog.csdn.net/Poseidon__ming/article/details/750925751 H- F7 z9 Q2 p2 [* V5 Z0 ]8 T
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