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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。
; H) D E: e) }9 o5 k/ a
0 k$ A" U% e& ]5 K9 \. t% `+ [! d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。
, ~( U% f% h" z2 _9 `3 q, e+ n" c8 f+ k' u, B
例如,+ V5 k. ^5 Y( [- K
* O {7 ~6 o& ?2 h
Total = 42
N/ I2 N, y0 X6 {3 z上述语句创建了一个名为“Total” 的 1-1 矩阵存储值42。5 Q. w' R4 b4 R+ I9 N
! `2 r7 _9 a4 p$ JMATLAB中可用的数据类型
- e/ B8 I( y ^9 e8 k$ T0 e! N; }" q3 r
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。
6 D7 z1 B3 G) \# j8 a
" x, H6 T& K0 i. N下表显示了在 MATLAB 中最常用的数据类型:
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数据类型 描述: Y; G {$ v4 e" y: r5 K
int8 8-bit signed integer: X* t+ u! q! {' [3 h" k
uint8 8-bit unsigned integer7 X5 f) m6 L5 X8 P% j- B' O' w {
int16 16-bit signed integer
8 W# O% y6 J" \7 A" kuint16 16-bit unsigned integer" K8 F+ x4 N" I9 [: K# g |
int32 32-bit signed integer
% }) i* W8 |7 Q; fuint32 32-bit unsigned integer7 p. @2 S2 O% O) D+ |! X' e
int64 64-bit signed integer7 K/ C$ l7 c% J+ @# Q4 K: ]
uint64 64-bit unsigned integer$ M i) q( O5 b+ Z! \3 {
single single precision numerical data
- C" i5 g8 f! O! V" M. G. Odouble double precision numerical data3 b' z% P- H) _+ x9 u( T9 V
logical logical values of 1 or 0, represent true and false respectively% Z) M2 J% M8 C% i4 M' q
char character data (strings are stored as vector of characters) U- H$ a! V. j
cell array array of indexed cells, each capable of storing an array of a different dimension and data type
# u$ O7 N1 `7 ]1 D" h4 vstructure C-like structures, each structure having named fields capable of storing an array of a different dimension and data type9 Z8 U5 G% n1 K t
function handle yiibaier to a function
7 M+ s) A2 g5 C9 }) M Juser classes objects constructed from a user-defined class
/ L, f9 c1 ~9 E1 d- F8 W+ sjava classes objects constructed from a Java class# ~ C6 K# u2 W9 G$ p+ j+ H
例子
6 @( Z, H- w. X* ?+ l0 f% V$ z9 g$ Z" \* K0 g( W" P4 W
创建一个脚本文件,用下面的代码:+ f1 P' p z3 I9 B. W( I/ X1 b& B* \1 ?
$ p3 _! u7 e& c" d3 F
str = 'Hello World!'
; B- m9 m% V T; m9 y% T" _0 D2 ]n = 2345
6 b& W/ t3 i/ b6 z; Pd = double(n)3 A. u6 j- r# K$ C1 |
un = uint32(789.50)$ F3 Y5 X3 S- {
rn = 5678.92347
4 Z+ t' ~, o1 f- r& s' [. w( Dc = int32(rn)( D" d/ _$ Z* U% }- ]) t! \
上面的代码编译和执行时,它会产生以下结果:* S& }/ t/ x! ~7 G V3 D
% [0 \- m& Q* E9 {! K! C" K' ]6 tstr =
0 P+ d9 n0 @4 }( R6 B- I/ u5 hHello World!7 |% N' \; A n* z/ p! e) s
n =
6 P0 w6 g# u) r0 g 2345
4 _2 k: c, d! T; L! z% }) z- Fd =
2 p+ O. e+ n7 z a# t# V2 Q* \1 m1 J4 r 2345
6 T& R! w& ^- ]& O! @: [% oun =2 I h% e9 t5 V. V7 I
790) `# I1 i+ Q H3 f6 |& n1 v
rn =
+ q2 ?, r; P8 ?. O+ ^0 z- z( t 5.6789e+03
) U' j1 y1 D% f! J; ~% |c =
: U, v" ?& Q( i7 O" I8 O 5679
9 o- C' Z) n3 Y5 Q数据类型转换. S" v, c+ M0 L$ Y, v ~
) @- G- I' p, ~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:+ D9 x3 E, u# q3 W# n; ~$ ^
" @; l. y3 x' Z
函数 目的/作用
9 P1 f: P% G% _/ Y: ~+ A/ ~char Convert to character array (string)
* u4 B* q- G% ?int2str Convert integer data to string, } u$ A( n u
mat2str Convert matrix to string
6 J" X" i$ a! D, O0 \7 Knum2str Convert number to string
5 s% R) `1 n* G& o# B* i+ sstr2double Convert string to double-precision value
, z( s4 h5 q7 Vstr2num Convert string to number, x1 C9 P; j- A4 U+ P
native2unicode Convert numeric bytes to Unicode characters
; a) a; J! T9 Ounicode2native Convert Unicode characters to numeric bytes% X5 h7 N0 q2 A! I
base2dec Convert base N number string to decimal number
1 r: K- U5 _0 \1 b0 F% V9 Obin2dec Convert binary number string to decimal number2 L$ ^- ]! _6 b! s7 o! i
dec2base Convert decimal to base N number in string& Q" H( M& e% e5 R# M
dec2bin Convert decimal to binary number in string+ T0 \5 h& K: [& w" n- C3 r( M- Q
dec2hex Convert decimal to hexadecimal number in string- H) E# M5 [0 i% g- @) m
hex2dec Convert hexadecimal number string to decimal number2 c! ~2 N' }% R9 ?
hex2num Convert hexadecimal number string to double-precision number" k/ q/ v. X4 N; A
num2hex Convert singles and doubles to IEEE hexadecimal strings
2 l9 \2 p& O( M7 Ccell2mat Convert cell array to numeric array, V- Q0 J' _$ e+ q7 ?! z
cell2struct Convert cell array to structure array
% a& W4 `# N- W: {' B! y6 \cellstr Create cell array of strings from character array
- b: W5 k9 A! n# m$ T+ Y$ D% Fmat2cell Convert array to cell array with potentially different sized cells3 h: \9 ]1 g, i
num2cell Convert array to cell array with consistently sized cells
( m/ }1 M+ ^4 i2 bstruct2cell Convert structure to cell array# p+ |- d o! I
测定的数据类型
! N/ d. L( J; j. k$ z y- T- ]. d% m/ H, [$ R# c7 ~9 D, p
MATLAB 提供各种函数标识数据类型的变量。$ b& ~2 I/ p+ q, X' o
# U9 \" u3 d7 Z) M1 W; w: P; _' m J下表提供了确定一个变量的数据类型的函数:; t. p" ]& m2 `- h
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函数 目的/作用1 @8 |( |+ s, E* g
is Detect state
7 H ]2 z$ ]& Z% O* m6 f/ aisa Determine if input is object of specified class/ w4 K3 Z( P) @: C4 K+ L% Z' J
iscell Determine whether input is cell array
- t: G* E7 ]' R0 t# D0 xiscellstr Determine whether input is cell array of strings
! m# q4 e5 V$ Y# Vischar Determine whether item is character array4 S+ D2 ] {2 ^ M+ I! m8 m+ W
isfield Determine whether input is structure array field \1 v' H* K+ T7 L$ Q
isfloat Determine if input is floating-yiibai array' C( s( R3 @( p J: d0 q% \
ishghandle True for Handle Graphics object handles/ X& l" p' h6 m7 W& k& A2 e) `- U$ S
isinteger Determine if input is integer array' ?* E; f3 y* p& n2 h5 X
isjava Determine if input is Java object
3 X) _2 J# N+ d+ _# qislogical Determine if input is logical array
) {, w8 |0 @( d7 @" T; Cisnumeric Determine if input is numeric array6 Y" l0 K% u* j- [
isobject Determine if input is MATLAB object
+ i1 `/ q3 p# d4 o( xisreal Check if input is real array' [$ ^& G& i8 k! Y8 ^ E7 K
isscalar Determine whether input is scalar
( _* E# F( n* D5 s0 b- C! C! Nisstr Determine whether input is character array8 l; Y: h0 M& [5 X5 S/ Y7 y6 c e5 T
isstruct Determine whether input is structure array1 l3 E' z- i; X {2 g. G, E
isvector Determine whether input is vector9 Q+ f0 X9 J* V' t# N" Q
class Determine class of object
! s% a M- b9 I" B) D1 D0 Ivalidateattributes Check validity of array
& P5 {1 }5 ?: @5 twhos List variables in workspace, with sizes and types- f, o" L, e5 E0 {* E' c1 g* c" e
例子# x" A$ d0 p, U* A/ o
# h0 y {, K- C8 n; _3 g6 l0 h
创建一个脚本文件,用下面的代码:
1 ^/ Q: L+ {6 y# B
, i6 x+ W- ~7 R! e* L2 rx = 3
& S5 I s# N0 D8 ]# v$ Zisinteger(x)
5 w5 L. D7 h* l# v) J! w$ t5 Zisfloat(x)
; U5 N# l! A2 |4 _- Eisvector(x)( J% _$ @+ X, l& I
isscalar(x)
5 \1 }8 @7 f2 Q, b7 Pisnumeric(x)
+ ` e9 A! V0 J/ ?. _4 E
& [" h; s8 {( s7 ~( Yx = 23.54
; m0 d' Z; |8 D0 Y% o% L! U& Jisinteger(x)
' D- R% `) Z! u2 Hisfloat(x)+ l; z. [. f5 a. o+ X: Z$ e" I1 L% Y! @' V
isvector(x)& [0 `0 k- v8 X7 Y8 u7 f& S
isscalar(x)
- `( n7 l9 F+ t' Q, visnumeric(x)
8 {* p3 |( h0 d3 Q9 w; D
/ z6 q8 h0 O; M, U" Gx = [1 2 3]
, W8 g5 _( r a n( o5 {" @isinteger(x)& x% D4 K( X r* j) x
isfloat(x)8 L" a- {6 V' H; w' t" J N( o
isvector(x)
) ^5 b k5 U' |' G& t0 [isscalar(x)/ F* |5 U. {# U
: A( X( S3 C% X6 C2 g1 O! Zx = 'Hello' X! L3 _+ z; A7 [% T2 {
isinteger(x)
1 I% P0 C F+ M; B9 F* x* W& Wisfloat(x)
& C5 i6 F8 h. X$ Misvector(x)
9 k/ U. e' ?+ U5 k* A$ B. eisscalar(x)6 m; y, [) u5 i& T3 i
isnumeric(x)
/ N% V4 G- j, K6 y2 Y6 U- J当运行该文件,它会产生以下结果:! C8 u$ w' U) s
' F" E+ J4 @1 L& m0 Xx =/ ?: ?: s! J/ g& }; P( v1 L6 E: F
3
% f# i& k* h* W2 y" a ^, O1 q' `ans =5 H2 z$ }$ M& ?, P
0' I. k4 r" ?) ~' m W; w/ t
ans =8 h. q- R, f/ x- N b# X4 y
16 H. L) H2 u/ C
ans =3 ^, p. X3 R( f) a* ~0 ~- ]2 n3 i
17 }' s: Y2 w/ N' y" p
ans =1 W$ Q0 I2 P+ Z, c4 C5 U7 u
1, k- i# {; C- F! W/ ]5 U$ T8 B
ans =
+ Y, t! N' k: w/ z 1
. R: P- F) ?1 \9 v* l% [x =& \7 }8 L# h* n+ |% h
23.5400& z) {0 a0 E& h
ans =
5 T* V" r7 z3 P; r) Z- l$ E4 g 0
. q) p, P8 b( ?2 vans =9 w9 W: d, o% ~) @& \
1
6 Y r) L3 k( ?7 fans =
. y4 ?! d) B8 l+ P 1
+ w8 x; r+ D/ L+ p7 F7 Ians =) G/ o1 q5 s1 T- C' P) b% M1 f: ?
1
/ c! E- Y: D0 d2 E8 o& dans = D9 l4 U5 R" j5 V _/ e
1# I: a8 D9 b: H3 x
x =* x' P3 Y4 h2 N# ~6 T
1 2 3
" y5 f5 ^% a; f! O, N. Nans =3 {9 j( ~: Q; c4 f
09 _0 V( Y4 l9 [2 c; j
ans =( h2 K. q: O1 u9 t, X! R9 X
17 j s! |( U) T, |6 S
ans =5 m+ k8 B( i2 `8 F
1; j+ a+ @$ ]! z$ R$ n- e
ans =
* T {1 i( I; Q' q1 P, F2 c 0
& v8 Q6 D! v: X* m4 ex =& L' W, \: J' q1 \6 O6 m4 w
Hello: P" m/ c2 `; {& S; Y0 L9 t
ans =
+ N! c, E+ f7 G- a+ m; h, ?. _ 0
: M3 f. l1 V9 s9 ]; H, h0 `ans =
3 e1 ^- |- q+ m* V9 @! V 0+ U2 \3 K0 A b( e, F# }
ans =
8 k Q: A }% _0 D 11 L0 }$ [9 n; W% i; \5 ^% G
ans =0 \/ V& a4 n( {: p5 |+ d" |- _" S
08 l+ ^1 X6 X/ G! A4 y
ans =2 ^6 [, Y# T% ~" a
05 X& b! @8 ~+ K# l2 M4 {
5 f! a" W7 w9 ~ e5 ~) S+ w————————————————3 |- O2 m) ^ f0 q# A6 [
版权声明:本文为CSDN博主「Phil__ming」的原创文章。
0 d/ C- o* r$ O' v! v原文链接:https://blog.csdn.net/Poseidon__ming/article/details/750925755 A. O) ?+ x/ o+ c
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