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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。
9 n" }, }6 Y! n( @$ U0 G$ N
7 X$ Q0 e- n! k5 ]; I9 L# N7 T9 e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。' } O3 g. e ~, Z! y
0 z7 H J5 J8 f1 c9 u
例如,
/ I9 ^( P! J3 h9 X: U) g* A* ^0 h- N
Total = 42
8 x O* a! z: {3 ?" `: m上述语句创建了一个名为“Total” 的 1-1 矩阵存储值42。
: f2 J- R2 C6 }9 X# k4 V* N2 u7 c4 U+ p. m" K
MATLAB中可用的数据类型
0 \0 [3 ], H+ V# U) l# ^. _% V
4 K8 p8 R* e* ]/ C9 RMATLAB 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。
, F! C8 I6 }- W
/ T1 y, t* A7 b' [下表显示了在 MATLAB 中最常用的数据类型:7 q: A1 }: e% y0 D
/ c$ C4 T! C) X, C/ B( \% J
数据类型 描述
+ s9 |9 {- @2 Eint8 8-bit signed integer
6 Z3 W2 j1 }; {1 ]2 X) E; @6 }uint8 8-bit unsigned integer
0 }* ]# k4 |( {) W/ i- ?$ a- j0 Q8 s7 {! Xint16 16-bit signed integer" \( i. W5 G0 z
uint16 16-bit unsigned integer6 M1 j" _. j$ Z+ I; e% m, D
int32 32-bit signed integer
+ _. X- {0 u% d3 t. duint32 32-bit unsigned integer
: V2 P3 g( p3 [* L) @int64 64-bit signed integer
$ b% M7 C2 j. N6 t- Puint64 64-bit unsigned integer5 j0 F& N8 C; S/ ~' k" p- i
single single precision numerical data; ], F: c! T5 ~ a
double double precision numerical data
$ c: j' z" U2 ]* Z$ [logical logical values of 1 or 0, represent true and false respectively
, }/ a, a1 S6 c0 e+ S* pchar character data (strings are stored as vector of characters)" a% C n0 d; o; Y
cell array array of indexed cells, each capable of storing an array of a different dimension and data type
$ x, i% W: e: G9 Rstructure C-like structures, each structure having named fields capable of storing an array of a different dimension and data type# @: L& K7 I3 ^$ R9 [4 L, c) V
function handle yiibaier to a function
8 c8 ]" `4 D$ O5 D/ z+ W' s9 buser classes objects constructed from a user-defined class# S+ h- ^+ J3 R
java classes objects constructed from a Java class7 ^( e$ W- h. o; K3 x! K
例子
{! f/ a2 u' t6 B9 `- S" x7 a0 q. ~, E: K+ a: d
创建一个脚本文件,用下面的代码:( x' L- |/ s. e/ g6 H2 S0 H% ^
1 {; }4 \% H. j$ H' A) [% ] str = 'Hello World!'; G8 q' G% c% ]: I( w
n = 2345
8 v) ^6 n4 @: M6 {$ F' n" C qd = double(n)
, Q- L2 e2 I% A/ f/ Q' g5 ^un = uint32(789.50)
$ M, q" n) M0 prn = 5678.92347! [! @ \0 `. ~/ l
c = int32(rn)
; K( [7 O! w4 t3 q0 }2 q8 N上面的代码编译和执行时,它会产生以下结果:
0 |5 B. V2 i" Y* S% r5 w p2 g$ Q: L
0 R0 Q7 Z: c. f1 xstr =
/ r: b" ~0 x. U8 A2 PHello World!
V D# |, X8 hn =
1 S, o* m- Q& b 2345
[! p3 x0 x$ d- @+ md =( d8 W; V# y. J: d& v1 s
2345) \! ]4 d1 t1 Q6 d- z
un =4 D% {) v0 z# A3 r$ K
790
3 {& v2 \, T, f* Crn =( m- ^. g% K! [. W( T0 ]+ l U
5.6789e+03
' c- W+ {" e% {. Dc =1 }5 [) U1 C$ e( B6 O
5679
0 O. I1 `5 q2 S: {数据类型转换. z1 W3 R) W1 e) k, J, E3 ?
, D+ e6 C6 f' a6 r" E
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:
( a/ g, D9 @( F6 M! h
2 C; r. i3 m# h0 X函数 目的/作用
# p5 E4 h) [" c# Fchar Convert to character array (string), @- s& L. F1 z6 C; N
int2str Convert integer data to string) ^3 f% E3 D3 Z
mat2str Convert matrix to string4 ], ]) i$ X0 h2 }) m1 Q. A
num2str Convert number to string' }# C) U9 ]! l. v
str2double Convert string to double-precision value# M! F1 v* [0 o$ ?; L8 w2 h8 t
str2num Convert string to number
8 G, P* Y, O' pnative2unicode Convert numeric bytes to Unicode characters
4 I: j; J7 ?7 Zunicode2native Convert Unicode characters to numeric bytes
6 B0 j7 u0 n8 }. qbase2dec Convert base N number string to decimal number
/ Z6 {! X1 O; T1 Gbin2dec Convert binary number string to decimal number5 c6 M7 B E& R2 }
dec2base Convert decimal to base N number in string" s3 @1 f, W# Y; }* K5 _1 |+ A6 `
dec2bin Convert decimal to binary number in string' Y. o" f9 v. y
dec2hex Convert decimal to hexadecimal number in string4 }1 r( f, q- ^3 E
hex2dec Convert hexadecimal number string to decimal number
5 r. U3 ?$ N& @# [1 Khex2num Convert hexadecimal number string to double-precision number
& Z3 V0 E4 g4 S2 @& v4 Z2 c1 Knum2hex Convert singles and doubles to IEEE hexadecimal strings! S! c5 K) w/ B$ Y8 U4 v
cell2mat Convert cell array to numeric array v3 |: |& m0 C; @
cell2struct Convert cell array to structure array
& {% [" \; @! }, L* ]cellstr Create cell array of strings from character array
" c: \" C; {1 p6 vmat2cell Convert array to cell array with potentially different sized cells* t' y9 ~& B" j0 u% |4 [+ ~( }# _
num2cell Convert array to cell array with consistently sized cells& h5 m5 W! S( z) M" ]$ @8 x
struct2cell Convert structure to cell array
z1 p: w+ W& {; i# b测定的数据类型4 v( i5 f' D1 }$ Q, `4 N
/ J$ Z( T' l" R9 l9 }! CMATLAB 提供各种函数标识数据类型的变量。
8 Q0 x9 Y/ [. [7 N0 U" @9 J3 x
, ~% H3 R1 } \2 w- L# X' [下表提供了确定一个变量的数据类型的函数:2 Q8 Y0 l7 A5 y4 `, \) f
# }8 a; V6 ^- E
函数 目的/作用
5 e/ M1 w1 K6 V$ m) B1 Iis Detect state3 P+ `! u. h! q* i H
isa Determine if input is object of specified class
* |7 e- P# ?+ I U1 t3 a) ?; M# uiscell Determine whether input is cell array- d m* Q& {; c2 F& r" L3 L
iscellstr Determine whether input is cell array of strings
9 m* A, J% N: V% T# K- U, Uischar Determine whether item is character array# ~7 b* c- A: T7 R! i
isfield Determine whether input is structure array field
3 S5 Q+ Y3 D# P- B" I6 l% E3 kisfloat Determine if input is floating-yiibai array# V4 R0 s8 x! L/ @5 @7 e6 O7 i
ishghandle True for Handle Graphics object handles7 A- o! D$ \) M9 k, l5 u3 d$ S* k
isinteger Determine if input is integer array
9 {$ [4 }1 M$ x- q K1 C1 p% cisjava Determine if input is Java object, z8 J' [$ A# J! R$ O3 Z: g+ M" M( c
islogical Determine if input is logical array
) S. U3 ]5 O7 o) Y1 z! `( c% ]' Nisnumeric Determine if input is numeric array
& I& m) B$ I* i0 eisobject Determine if input is MATLAB object2 |' V3 e6 ^8 v# N9 w# c8 }: n
isreal Check if input is real array: v0 W% e3 L: A
isscalar Determine whether input is scalar( u6 |3 W# L" N' O4 o( t
isstr Determine whether input is character array$ l9 i! [. s* \/ h; I3 J: m, g
isstruct Determine whether input is structure array' p1 W2 I' V' f* p. n
isvector Determine whether input is vector E# Y9 y9 H! f5 ?9 ]
class Determine class of object: S7 H2 \& Y# F
validateattributes Check validity of array# v3 ] j( T% ?: b- K! h
whos List variables in workspace, with sizes and types$ Q% L) t( Y& |* c4 ?1 G" m6 _' [
例子
0 l9 T/ z3 k: ~1 c, k" m" j. Y) g
# q* l' n, f# f- J) }7 ~ K' \创建一个脚本文件,用下面的代码:* b7 p* n$ ?: n( o" v+ m
+ d$ I$ p1 e2 L9 o7 e* [; A' }9 O
x = 38 f! |! V, ?( Y
isinteger(x)
4 b9 o3 E8 u$ J" y5 ~isfloat(x) e% U6 ~- p% y+ o# ^0 a
isvector(x)
2 I- F+ p0 w% [. j* g/ v2 Kisscalar(x)% ]! A* H- w6 V w% j% v M6 L
isnumeric(x)* c/ l8 d" g+ i" i/ l R
5 G/ e, h4 b* e8 ?x = 23.54. F! h( A! C0 \1 J9 U4 f
isinteger(x)
( @) O2 ]; _1 [+ d& {4 `. p; Uisfloat(x)5 u1 l) D- A, {7 A, [1 K( w
isvector(x)
- c' Q( x7 Y$ @5 m1 f: l- K) Disscalar(x)
5 o3 [ Q0 s2 F& [8 L5 q, e# D" _/ Zisnumeric(x)
3 }2 k" S0 t: [; P
$ r3 b) n0 i8 Q; ?x = [1 2 3]
6 f# H2 F8 Z5 X, Cisinteger(x)
4 r; ~5 x+ P9 _) l- sisfloat(x)
' i* x/ I7 z6 Lisvector(x)# ^1 s* |+ D' z: V {
isscalar(x)& `% [, D9 h+ P3 f/ V4 K7 N, Q" T
3 z4 C& N6 a' l* {) j, m" _x = 'Hello'
1 ^! S" B, }+ O: Bisinteger(x)
Y! T/ D5 V9 a2 M% G% l! `- @isfloat(x)' _; X; v) W1 c0 E/ e4 {+ [( A8 m
isvector(x)
- p' Z# k% H6 g% |. J" d% yisscalar(x)
% r* C8 X( A8 g! S. k6 |! zisnumeric(x)
# I% E. D" k9 V当运行该文件,它会产生以下结果:
! l1 j& \8 \5 h. B0 |! o) h; c) h4 g' T( r e0 }4 v7 G i8 z0 M
x =
3 m- _, _' Y5 m# ?, s 3! ] w5 X( u& E9 Y: Z
ans =6 z2 ]) Y% R) E' g% H* H3 m1 q
0
2 I* i: I3 r( d( tans =
" U/ P6 ^& h; c7 L 1
7 y9 w1 {5 ^% v. r+ I4 Fans =
8 ~: K9 K9 |" ^. f, {( R' ^# q# c 16 t4 T; q' Y4 n# V: c" W0 S. h
ans =
9 `1 [( w w5 T 1
' W4 j& R i5 b y7 a8 A1 {2 Z& Qans =+ Y& Z; m! {- L
1" K8 {- u; y' o9 {
x =
# c/ G2 i8 ?1 t$ [ 23.54006 p0 o: X6 b$ f6 s: x
ans =5 m# H2 Z3 z$ e( u2 p8 @4 O3 D
0) s# T) B% D, J% a
ans =6 ?2 r3 n/ m' \: o/ b0 e
1
4 r; g0 ?1 o y# D7 mans =
" Y _" t" H) y/ N2 C8 S 1! K" ^8 \/ d: k+ J% \
ans =
0 ^! S. X1 ] e* { 1
& L% J" k- J3 m$ p/ Hans =
" Q, ^, Z4 u0 } 1
6 E" O* q1 q8 ?# Jx =
; D! o4 K6 I+ K: ^( x' d( ? 1 2 3
. U: `2 G, q$ J9 Z8 v/ L! ^7 @ans =
+ x3 d m, g; E# @) m# V6 k; f 0
" P3 B9 i. H2 K! F' t. ^& v9 E2 Sans =
# r4 @! T" J' w+ x i+ Y" n( z 1
. a8 t* O2 X# p4 Q& H7 ~3 ~ans =
; _4 B2 d7 t0 b5 ]0 H* Y# R! Q( { 13 I1 r9 p5 S5 l
ans =: V( t& K9 B$ y+ b- ^
0- |2 _9 {; S9 R2 R% K, V
x =
" i. `8 ^ P2 y1 D1 ZHello) A9 X9 J+ P6 B/ J3 s& q# f4 ]
ans =
2 b" P1 \# K% } 0( Z1 s! P% r% l: p6 [! c
ans =' \2 |( @2 {5 M
0
( L3 Y4 e5 e" J8 E: x& X0 A9 Mans =
4 @5 c! g' r/ j# |5 G 1
) q. L# K+ e" t" r* Q# fans =# Y& |3 E* y" ] ], `3 ]* L/ d! |
0
8 |$ ~( C/ F! |5 ~7 [ans =
# b7 o9 D: }# F, C 0
' R/ {5 I5 m" \2 ~: J. j/ O% Y
9 w& X4 {/ u; |————————————————% @+ r l G& B7 j: J! ~2 N& P
版权声明:本文为CSDN博主「Phil__ming」的原创文章。% F9 g+ \' A5 V6 D5 ~
原文链接:https://blog.csdn.net/Poseidon__ming/article/details/75092575
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