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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。) O* M2 y+ N$ k7 _1 \+ [
- n1 _5 s ?& U9 E* V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。4 I" O, }+ B+ H- x
1 Q7 {7 `) N# Y" {例如,
7 ~, Q1 n/ v+ p% t! o/ R! c i" X3 }7 W3 G0 J
Total = 42
9 y% l2 o5 @6 h& f上述语句创建了一个名为“Total” 的 1-1 矩阵存储值42。! W/ a. m6 |; m+ \
8 {" i0 h( _* M3 Z
MATLAB中可用的数据类型
$ y$ t. V, z% u
, L e3 |8 N( I2 nMATLAB 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。4 u* V$ d" [6 V2 Z5 _
; L2 Y" ^5 A% ^; z: n* {
下表显示了在 MATLAB 中最常用的数据类型:6 w. q& Y+ W: X+ I( }5 T% L
4 U0 A/ t9 q! b数据类型 描述
% E1 d; {. Z' O; ]! H/ F s% b: I0 F3 Sint8 8-bit signed integer
: c& r; E$ p- g% Ruint8 8-bit unsigned integer0 ]3 t& L' g: ?* }
int16 16-bit signed integer
+ A4 O0 I: B R9 z. s1 ?uint16 16-bit unsigned integer
; p8 {! e3 c6 G0 }3 E# ]8 rint32 32-bit signed integer) k, K: t- `; G& @5 R
uint32 32-bit unsigned integer- q0 W$ z6 u1 ?$ H3 h5 s
int64 64-bit signed integer
' K( G2 A1 V- M* X1 S# n |uint64 64-bit unsigned integer
3 b6 O- c" Z7 o$ _* F" c2 o4 ^6 q4 rsingle single precision numerical data- L* _. R# F( ]0 u3 ?3 H6 {% `( H5 E5 Y
double double precision numerical data
k0 N; r1 G$ w0 w3 t8 M( ological logical values of 1 or 0, represent true and false respectively
, M4 ^6 q, t1 H& C3 A. Wchar character data (strings are stored as vector of characters)# c x5 [+ Z+ n# N8 P
cell array array of indexed cells, each capable of storing an array of a different dimension and data type: L5 [5 R/ E# f
structure C-like structures, each structure having named fields capable of storing an array of a different dimension and data type2 j5 h2 K0 y3 `! d0 i
function handle yiibaier to a function! t0 g9 x* s3 a8 T
user classes objects constructed from a user-defined class7 e6 c1 W: S% J1 D+ l) s1 b
java classes objects constructed from a Java class3 |7 q2 q F C6 S% s2 `
例子. r/ Q6 d2 G! r
" H4 Y) i2 s* ?! t" C; `, s
创建一个脚本文件,用下面的代码:
, n' y- @( N8 X
+ W8 [" D8 X$ H9 d) W str = 'Hello World!'
. p! l3 c/ s$ t# B& @9 Z$ Bn = 23450 j% t# N! S0 N
d = double(n)% M& E0 F7 ^; J# M
un = uint32(789.50)
, X$ h: u# ]7 G* H/ mrn = 5678.92347
9 m1 y5 |0 Q" e( d$ ^7 i2 ic = int32(rn)
/ |5 a& I) {1 A/ j上面的代码编译和执行时,它会产生以下结果:
) P4 [8 D" a3 |5 e& U: z t' _
) Z/ n: Z+ r6 k6 ^0 {' zstr =$ y% X5 {6 x0 u8 l( r8 R, y
Hello World!3 I$ \! d1 H5 U6 Y% E2 H
n =
* Z3 y; r2 [+ L' o$ M5 D) H& c 2345) r! ]" v0 H7 f9 F
d =4 v/ d- p! B& {: i0 R1 q$ F' p
2345
h3 t5 k5 \9 ?' c; [: F" Iun =
% T) r* P, G! | 790
& B" G, m- s; m& }' a* ?* nrn =& X( _& N! @5 N2 K8 C! y9 @) u, J
5.6789e+03' _1 f5 E7 e# I; g4 t- M* a- n
c =
+ `/ |4 ^: e" ]% | \ 5679% {0 s' ? p1 d0 t4 m6 b
数据类型转换
# [. N/ @2 I$ |; ~! b9 L; L) A
* F! X8 _1 h2 Q9 h& y0 F _/ YMATLAB 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:
1 S3 x3 I- g; d& _8 `2 t v' ]
函数 目的/作用: s8 x) K/ s* j8 S P( y5 \
char Convert to character array (string): n0 j! n: D* T! s
int2str Convert integer data to string# w" X5 I1 @5 w# R
mat2str Convert matrix to string
4 n* W8 A0 Y/ @1 u8 s+ |num2str Convert number to string4 ]8 ]0 M; v# I5 t
str2double Convert string to double-precision value# i+ z5 Y" e' R
str2num Convert string to number$ f/ X* I/ `7 H& q# b
native2unicode Convert numeric bytes to Unicode characters
- p2 c7 @4 b9 |; @; qunicode2native Convert Unicode characters to numeric bytes
- j2 m, ^3 L' G: j: o) P/ e- E; P# ebase2dec Convert base N number string to decimal number
) V( z6 `2 K2 m: H; @0 S& cbin2dec Convert binary number string to decimal number4 v- W; [) e1 E# H
dec2base Convert decimal to base N number in string
! B2 O, U8 W, U1 Sdec2bin Convert decimal to binary number in string
5 f# W$ P/ X0 Q' r( m9 bdec2hex Convert decimal to hexadecimal number in string
L- p& S% i: v% O% v- V! d6 ?$ Dhex2dec Convert hexadecimal number string to decimal number
8 Q, X7 P P; z9 X. }* ^hex2num Convert hexadecimal number string to double-precision number' G: ?* D/ G8 M, K2 [+ @3 k- l3 l
num2hex Convert singles and doubles to IEEE hexadecimal strings
( k" V6 n- t1 Ocell2mat Convert cell array to numeric array
: J1 p3 e& \! L3 Gcell2struct Convert cell array to structure array9 n+ t0 P+ J- F' \
cellstr Create cell array of strings from character array2 L" U1 h, E7 Y/ |# y2 N
mat2cell Convert array to cell array with potentially different sized cells
; y! {# I( G4 R T( c4 R0 D' enum2cell Convert array to cell array with consistently sized cells
( Y2 o9 O( t bstruct2cell Convert structure to cell array1 j( `/ i7 G4 w# d: t
测定的数据类型* E. Y$ a u% Y/ {% Z6 N
9 v, t0 q+ i0 A: K& }1 EMATLAB 提供各种函数标识数据类型的变量。9 J, c- l8 @. ?* q: |5 W( m0 c
( Q6 B$ D5 z [0 X
下表提供了确定一个变量的数据类型的函数:
1 i6 R! n2 y! M* f% N. R: z j1 H! O1 G
函数 目的/作用
* K0 H0 C: |9 j& J7 ]8 eis Detect state. U+ P1 z; E6 @( W
isa Determine if input is object of specified class) Z2 y) ?0 L6 _6 R1 R- a, {& }% _. t- a
iscell Determine whether input is cell array
0 l/ T+ e( U$ o8 N& n7 _! E; Wiscellstr Determine whether input is cell array of strings% m Y5 G8 C( F( p
ischar Determine whether item is character array
4 T: u9 N6 r+ k) J# iisfield Determine whether input is structure array field
9 T+ `: t& H/ m8 disfloat Determine if input is floating-yiibai array
! H0 `/ j. k" f, D2 ~- Eishghandle True for Handle Graphics object handles
& f/ K* y4 `4 z4 @! ~: ]isinteger Determine if input is integer array
5 U7 A, Y/ z& I" X6 pisjava Determine if input is Java object
4 m9 m% W( k8 m8 W& M9 kislogical Determine if input is logical array
+ P9 e! E* f( ? L w; Sisnumeric Determine if input is numeric array
+ v! {0 u0 p# w# k: {7 x. I6 k ~isobject Determine if input is MATLAB object
* E1 W- p* ]0 _+ Risreal Check if input is real array
- Q+ |* T3 a* m, Kisscalar Determine whether input is scalar7 p! m1 @& g; _
isstr Determine whether input is character array+ I: ?: p- E% H# g* i5 `$ P
isstruct Determine whether input is structure array! Q% Z8 N! S% u4 u9 d/ Z1 a
isvector Determine whether input is vector
9 W5 g( c& E0 v; M/ i4 }) D+ Wclass Determine class of object6 b+ \" t8 }( b" J+ K3 P
validateattributes Check validity of array( P4 E$ W- C) ?# \) v
whos List variables in workspace, with sizes and types
) Z) M* [; Q/ D0 T' J例子! k: P+ ]* K/ @/ m* A; `1 U
% T( b0 B# f1 t8 |( r- l
创建一个脚本文件,用下面的代码:9 k( `6 J+ J1 f
* w- Y; {9 _" W8 ?, Ox = 3
1 g2 [7 j' U% l& nisinteger(x)3 k, N8 ~+ V3 r Z: w( q
isfloat(x)
, Z# R' ]: O, u6 p8 d( g* qisvector(x)! U5 _; }( _8 @" n1 T5 F6 R* S
isscalar(x)
2 p8 {+ N1 @3 |; t& I; Oisnumeric(x)- N$ I. ~8 |4 S i9 r
3 G( l/ E% y; w! p7 m# gx = 23.54
( ^% T0 S& S% \1 pisinteger(x); M& R( Q+ u0 k+ {7 D, u
isfloat(x)
- v+ w, f2 g5 t* S3 R$ q4 L9 c( Pisvector(x); T3 P+ s+ W: J, \( j) I3 H
isscalar(x)7 B8 h7 `% O( f6 i8 h5 r
isnumeric(x)8 h/ b O- S U: D& b1 y# K
: Q' {1 }, L; o7 K \& C y
x = [1 2 3]
* M8 a, l3 S: X) @" L; W4 e$ |. Lisinteger(x)
4 T& [0 l; m' j8 V& S$ E' C# }isfloat(x)* m5 Z+ u6 r3 @8 z( ?
isvector(x)+ j( W, X- a) Z% w
isscalar(x)
% n' ~0 o% M5 y! B" Z6 Y) V* h3 j, g% c: c
x = 'Hello'* ^- j9 e9 H: U8 f9 C2 p4 g, U
isinteger(x)
7 u! o( ^" y. c8 Tisfloat(x)% `! p p" s! ~. {
isvector(x)
( x k2 n* N7 T( W3 o/ fisscalar(x)* f+ a7 \, Y# w; s; l* T
isnumeric(x)* p( w: g2 T% g4 E/ d
当运行该文件,它会产生以下结果:7 b2 q) Q% ^! u( K0 W
r4 {3 n# U8 s' o" N. `( qx =1 o8 W# |: n0 F* T6 ` {( _8 G$ O
3
0 @' p4 z3 N9 U. ^ans =
% b0 U- N- k m$ a 0
! k: Y# t' Y/ G7 } b& y; Wans =
! ]- _2 G1 h: i( ^ i 1
0 H) Y, H2 r- e# q4 g! d" `ans =
; K: ?! L; E d9 _9 l( i5 \6 G 1! j5 ^. c' |9 l3 ~$ ^
ans =% `2 T6 h4 B6 ~3 g& g9 U
1( j& }4 H$ x" i+ j( F# J
ans =
7 G3 \; C& [0 I 12 [. r# _: k' f7 h5 H% X- `
x =" Y# r7 U% |0 j
23.5400
2 f: e* V5 `7 u7 d* rans =
$ C3 x! _1 ^& `( } 04 i1 u' q: O+ [
ans =
- R& e2 n- ^# p. h3 q9 j 1
# Q3 m( F# _* R4 S7 x7 k6 Uans =2 u; o8 B# \" O! M0 G: c
1% u# [ K- I% s$ e0 ]9 R
ans =
' b f8 a; a8 |9 O! E! M3 l* d 1
* ]8 N- [/ [1 V( i x6 Vans =# h: U F6 e# h0 _3 [
1& ?' v7 J! h( z# r
x =1 o0 x/ o& M& q8 ~0 O* |
1 2 31 u7 K' D, H0 p+ r X8 @
ans =
4 M7 [* V t0 {0 b2 C" q, N 0, M) H2 K1 P5 t
ans =
7 T9 }+ h+ k) Y$ s6 e7 p 1
% F# Y; k6 U' B% }ans =2 k. w- ?9 h+ ?/ p
1& A8 F$ O! E' Z0 o) t8 m+ ^7 L
ans =
5 C- H& c2 V& L( E+ W; A 0; i: a7 j% H% b" R4 ?
x =
) l' C. I9 o! O' c( f3 n) C, R! K% uHello
$ {/ O! L- [3 `' ?9 Kans =
4 P6 i2 U9 `5 ~1 Y" s/ E 0; `2 C6 J M, N: e% B
ans =
+ b- X% N9 [8 o1 K3 O- t 0
' V- P. G) |% jans =8 i$ H& ~$ }1 j: t' Q) s+ o
1
0 {. x( H' G4 ?4 L# @, q# D* y: @ans =
. ]/ b1 |; U9 `% v; N F 0
4 H3 Z: m' J" B) {0 J$ I( O- ians =9 @1 x1 y7 u3 i. W
0
$ } o7 F4 y C8 |6 @1 I9 R! m; l8 w z, I: c
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/ N, R. W w- N% j ?, Z版权声明:本文为CSDN博主「Phil__ming」的原创文章。9 j5 Z2 s7 Y: x
原文链接:https://blog.csdn.net/Poseidon__ming/article/details/75092575
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