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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。
$ \. g2 r9 O- O. h
, L1 n" }! |1 o" Z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。 l) k- C& |6 e% H: T2 X
7 k# K1 l% Q: O1 Q8 p( w4 x例如,
+ F+ F2 l2 m# i! o, F
. X: J& j. Z+ c9 f' Y; m! _/ aTotal = 42
8 r" D+ _, z- ?& U. K9 w上述语句创建了一个名为“Total” 的 1-1 矩阵存储值42。# R- G6 H! V2 p$ T/ s1 o: b& q7 o
' E) E `( [$ I9 |MATLAB中可用的数据类型# B* g) G8 [8 M0 j z3 s0 x
9 Q$ ^# N" ]2 E7 V6 J- f" b
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。
: O4 f8 f9 q: ~; w I# D3 X
' y+ s3 |6 @& o- Y; H2 d- J, l4 ~( g下表显示了在 MATLAB 中最常用的数据类型:
~3 b- F9 {% t4 P& H. k; O( [( r n' x# \4 _# H1 W5 N
数据类型 描述5 @/ J d/ e% T- ?. o2 w
int8 8-bit signed integer/ ~3 g7 f, \8 _- ]& Q! f
uint8 8-bit unsigned integer
1 k8 h Y7 [( j/ r. ~; Zint16 16-bit signed integer4 C) Z" p9 s- I1 O T6 B+ O! j/ v
uint16 16-bit unsigned integer _# X0 V& R7 C, ]- E9 {
int32 32-bit signed integer" G$ Y! M& D4 u( E( l0 A6 }& j, C! M
uint32 32-bit unsigned integer
7 L0 o% ]/ `2 g) Eint64 64-bit signed integer( j# @0 K4 e4 n6 r. Z$ i
uint64 64-bit unsigned integer- f2 y3 i: b4 i+ j8 P; E$ u
single single precision numerical data& W0 L+ Y' U: B: q3 G7 X6 q
double double precision numerical data' P8 f& k- B' U S
logical logical values of 1 or 0, represent true and false respectively
5 T: H3 t+ X) s1 g+ f, l6 I, Echar character data (strings are stored as vector of characters)
$ O# ^ p( I1 T1 P! Zcell array array of indexed cells, each capable of storing an array of a different dimension and data type
2 s/ E# v! N! C: wstructure C-like structures, each structure having named fields capable of storing an array of a different dimension and data type
2 m# C' ~2 i8 a% d% q$ ~" B/ efunction handle yiibaier to a function
% M6 u; y) q% J5 E: O: duser classes objects constructed from a user-defined class
2 b/ ^6 P7 ?8 N9 q2 Y9 L9 m" wjava classes objects constructed from a Java class
2 X9 Y" X4 Y" p例子" s1 L' e% h$ S) j
# H' S* p9 }) u7 u8 K8 F$ E A
创建一个脚本文件,用下面的代码:
& S2 _; M" e }0 x$ A
m- {* G* n# U str = 'Hello World!'
3 H4 a8 M- m# b k0 t: mn = 23458 A' g6 r' r$ q* [7 x
d = double(n)' T, K6 j3 ^# a' w6 {
un = uint32(789.50)
+ I. y) ?: W7 p8 F% J7 H0 {rn = 5678.92347
' n: M9 h! l5 _3 N& K. R$ z) X- H" hc = int32(rn)
+ q5 v. K2 k& Z+ `/ P上面的代码编译和执行时,它会产生以下结果:
- ^" s9 R0 s8 v0 s+ b8 }7 M4 Q9 h) T; L2 ?( x, p
str =3 }+ X% U8 X4 R# B# E: l
Hello World!
+ c R6 {$ J0 d# T$ \n =1 ~3 M+ b& w0 L' d! M- s; n
23451 B/ M2 u! U" |9 O$ G: S2 C
d =
7 d. I; D& o6 D% \ 2345" T" R9 T) h6 w' i: x* ~9 m# X: Z
un =
/ ?0 S3 T" P6 k9 ^8 P5 _ 790: ` m d$ A0 j+ ~3 I
rn =
$ ?8 ?% K# z7 f ]+ S, D 5.6789e+03# |- H3 Q! {- J$ I% g5 _
c =
* f: h# [9 @# a- [1 y 5679# X4 X$ `0 W( G V8 z5 K! V- P4 v
数据类型转换" P9 L* Q t. V5 |) ~
1 _. v l6 F4 g$ U
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:
; X3 g! U( }8 U: A" W" ^& }( o, ]- M9 c, |2 a
函数 目的/作用
* L/ ~: A% _" Gchar Convert to character array (string)
6 r' X) ~0 `% m) p5 J! ^int2str Convert integer data to string
; t( c, }1 g; U y: ^+ Gmat2str Convert matrix to string9 V) r2 L0 _& o& y6 E9 |) f
num2str Convert number to string ?; G6 R) O" r4 ^7 Q; d
str2double Convert string to double-precision value
" m; B1 o+ c: v+ estr2num Convert string to number! X; j. j9 }; [% V2 x* N
native2unicode Convert numeric bytes to Unicode characters
8 i9 W/ m6 c0 s; T8 @2 Bunicode2native Convert Unicode characters to numeric bytes4 \3 Y) s+ {3 f, h7 b) B: D
base2dec Convert base N number string to decimal number
\! `3 r: U1 D1 Bbin2dec Convert binary number string to decimal number
% b$ l4 k0 v7 D, Ldec2base Convert decimal to base N number in string
( T6 F& O" z& Z, g, M6 |! odec2bin Convert decimal to binary number in string& S! }7 }7 E2 e
dec2hex Convert decimal to hexadecimal number in string0 g6 J4 ~0 E$ |( ^* K5 j
hex2dec Convert hexadecimal number string to decimal number
, V& @: Q9 Z/ Jhex2num Convert hexadecimal number string to double-precision number& j) y3 x" M4 M' J' i4 Z- d" Z3 ?
num2hex Convert singles and doubles to IEEE hexadecimal strings9 _4 \# k# b/ a1 j" n4 M8 K* j
cell2mat Convert cell array to numeric array
1 \0 ^, h+ }+ `) Hcell2struct Convert cell array to structure array
# t- F {1 f6 T6 `cellstr Create cell array of strings from character array
5 y u% f: n2 ~- `: B) X3 pmat2cell Convert array to cell array with potentially different sized cells
' E# q4 {7 }5 V9 G1 h7 gnum2cell Convert array to cell array with consistently sized cells) B4 {0 o/ T& v
struct2cell Convert structure to cell array
k) z5 `2 O4 _5 o0 n8 u测定的数据类型- l6 S" c+ i) r8 i/ F
% `# m" \) x, Y$ J
MATLAB 提供各种函数标识数据类型的变量。$ Q" O. u0 z, `1 n3 q
/ K9 D: k' L# Z4 {* d
下表提供了确定一个变量的数据类型的函数:
# O' \8 N- }: Z: n! l! _5 b
8 s4 s A: O5 h( i4 m# L# M函数 目的/作用/ M" ~3 m1 i$ h7 t1 R- Q6 Z
is Detect state
+ f* c* C8 B& P/ T o; \7 K. Wisa Determine if input is object of specified class* } k7 _# V6 r! u# P; S j
iscell Determine whether input is cell array
; ?* j5 g/ P: @" x: d) e: niscellstr Determine whether input is cell array of strings6 ~0 v6 E1 a, j, i3 b- Y* T( T
ischar Determine whether item is character array
/ t+ F$ r7 z1 ^4 D4 q% qisfield Determine whether input is structure array field
9 N& b, `. w/ B" @0 F# i& O+ Disfloat Determine if input is floating-yiibai array! @' \/ W* q8 c. F; ?
ishghandle True for Handle Graphics object handles) P4 l" g4 {; I# j- U5 b2 F/ p
isinteger Determine if input is integer array
4 `& F) K( G7 D9 ?6 M$ L" {$ b2 Xisjava Determine if input is Java object9 h& O; e2 K! \2 e: [4 X1 G1 v
islogical Determine if input is logical array: e! B9 Q, `! K& x# {8 `" W4 y
isnumeric Determine if input is numeric array' o& Q1 T6 n/ Y9 K9 H# V/ \
isobject Determine if input is MATLAB object! J# d6 K7 L# c$ H. ]
isreal Check if input is real array
( G$ ?8 y+ q- Xisscalar Determine whether input is scalar
0 v( d# w& \, l+ K5 Misstr Determine whether input is character array8 H! T7 D4 w, L& n. T4 D
isstruct Determine whether input is structure array
% N8 M( O# d0 u5 }6 b" n% Wisvector Determine whether input is vector, D2 j) j6 V) c3 h' `6 ~
class Determine class of object! w6 A5 C7 H5 v# C3 w. u
validateattributes Check validity of array
@5 ?8 m4 y2 } s2 Ywhos List variables in workspace, with sizes and types
3 z4 c0 \( x T0 i$ D ~/ w例子
. h7 u, T! O" J! R6 q' q3 Z5 E- j5 b8 Q M' ?
创建一个脚本文件,用下面的代码:* C( O7 m( S+ o& J
5 f, ~+ w: P. H1 s fx = 3
4 u6 y" W( P* h5 Yisinteger(x)
0 w! g% Z# Y8 `# u' L7 b& uisfloat(x)
. O0 c* U7 p* l, L Tisvector(x)( A2 r( u& O8 g3 ^7 W% ]3 D; p! v
isscalar(x)
- {- y$ k7 M6 }( j9 w/ Yisnumeric(x)& v/ |1 Y/ r: x( c2 _9 Q
( J( A+ h8 s8 \' Z( y6 Z
x = 23.54+ ~8 _- J. t7 e
isinteger(x)" N1 |$ {- L8 G! D7 t2 |5 |
isfloat(x)0 O# [% u* `/ L1 L1 I& R7 t
isvector(x)! h1 s0 j7 D4 k p$ R
isscalar(x)
4 U4 h' N4 v0 V1 z: `2 t% Nisnumeric(x)
C) H# L9 ]* H7 C, g9 x/ _: N0 N2 C2 ^4 w4 r, e& [7 P
x = [1 2 3]
6 r% ]" y( w" o- ^8 R2 @isinteger(x)% J" j2 i8 U7 f% x4 I4 {- A
isfloat(x)/ j: ^0 j2 }0 _$ n3 y
isvector(x)
' @2 x/ H* ~9 ?6 V2 `* W+ m& ]isscalar(x)' I* N1 x e5 ]( `; R7 L
) L3 x- O8 N8 ]# h. f% t) y
x = 'Hello'
+ ^ j' f6 i( V( x& Z- oisinteger(x)
5 n/ `% p- J: J: u; V7 Zisfloat(x)
4 k& i: B& D, d1 _! G7 yisvector(x)+ G: m$ O2 I, |" D. J( ^ F2 j; H. M
isscalar(x)6 `9 k+ I- C( N( @' \+ \
isnumeric(x)
7 p9 I3 O1 B4 w3 D8 b% S当运行该文件,它会产生以下结果:) Z/ q/ Z" c! e# z% i
( l, A5 a" |. k" `
x =8 K, X7 X8 Y* i1 u! A% b: F7 P5 C
3. M6 U; o, t; N% ^. H5 Q
ans =
/ ]0 q" i% J& y 0
7 S& w; \2 G6 A$ s$ G2 {, v$ J) ians =
# h% D) j) K. H 1, n( N. d3 P- V2 W# |1 M
ans =" Z3 Q$ L0 h0 m; v2 Y2 x
1; S2 A# }- p" ~
ans =
0 O8 u o9 A: e; ~3 t 1' N+ G! \+ `/ Q/ ^
ans =9 k7 Z t, s6 v8 g6 N& o. Y
1# S, ~$ B: c$ H; j0 u' U
x =
2 u: ~0 s3 t7 l+ J 23.54005 o& p4 x- [) d" q0 K2 j' e. ^* M
ans =
- b' d+ P! v$ J4 f; T# L" V 0- y- C8 @& x5 E
ans =
. U* k* Y5 P: s: P 1: n; Y" n; D9 }2 M
ans =5 [+ P# f2 G* |7 m
1
& ?4 S4 C! @" k) g" z. mans =
, C0 I$ V; I% K4 I t M 1
6 ?: {- H& V, C. h2 R1 ]2 A7 S% bans =, a1 Q# H/ F6 Q7 s
1
& s6 w5 r- {/ R1 u8 {9 ex =
, U0 a& X8 k; g+ W% W: M: C 1 2 37 q+ w$ U, j, X/ \+ D5 n+ k; b
ans =
3 C0 k3 [9 O$ n* m/ i) j6 O% b+ E 0" L7 g: Y1 |% w3 [9 i6 k( E9 y
ans =
$ Y& |) i: Y) O0 U0 T$ N 1
7 Q4 z" |5 P. n' fans =
4 B7 ]- y5 h$ f# @9 f' P$ F* w 1
; V2 ^" p( j7 Bans =) W) `0 R0 y8 _2 O8 x: {
04 l, y' L7 F Y
x =/ L9 [: n, ]* T& U; r0 [5 |
Hello3 D- z0 `3 e( @8 s1 m! N% j: `
ans =
. z# R l; p! H; Y1 |% v4 b$ f 0) |, H* u7 S) A- o& _( s _
ans =( P& v, |( I3 i2 l) l k0 T3 K1 J2 {
0/ v6 j. z' e6 Q0 R0 K
ans =( T' q+ @6 L' R& ^
1
. R! P9 p+ T2 a1 |3 Eans =/ U: U- Q/ R' n u$ e! ?
0/ J$ M5 R- t& |7 x+ q( h" [, ]
ans =+ w ~: J$ ?& q n, ~4 e
0 e- F; X! b4 \1 j* I7 ^+ a
, w ~' Q8 B; U$ q
————————————————
: F& O w, W3 G% n版权声明:本文为CSDN博主「Phil__ming」的原创文章。) {' M+ d' q7 N9 b4 h4 J7 O
原文链接:https://blog.csdn.net/Poseidon__ming/article/details/750925757 O, V% ~8 G0 ~: g% l8 C! D+ [7 A
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