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strvcat（不推荐）垂直串联字符串

官网链接

function s=strvcat(varargin)
%   https://ww2.mathworks.cn/help/matlab/ref/strvcat.html
%STRVCAT Vertically concatenate character vectors or string scalars.
%   S = STRVCAT(T1,T2,T3,..) forms the character matrix S containing the
%   text T1,T2,T3,... as rows.  Automatically pads each input
%   with spaces in order to form a valid matrix. Each text parameter, Ti,
%   can itself be a character matrix.  This allows the creation of
%   arbitrarily large character arrays.  Empty character arrays or strings
%   in the input are ignored.
%   形成字符矩阵S，T1,T2,T3，… 按行排列
%   每一行的长度一样，不足的用空格自动填充
%   Ti可以是字符矩阵
%   输入中的空字符数组或字符串将被忽略%   S = STRVCAT(T), when T is a string array or cell array of character vectors, 
%   each element of T is passed as an input to STRVCAT.  Empty character vectors in
%   the input are ignored.
%   当 T 为字符向量元胞数组时，S = strvcat(T) 将 c 的每个元素作为输入传递给 strvcat
%   输入中的空字符向量将被忽略%   STRVCAT('Hello','Yes') is the same as ['Hello';'Yes  '] except
%   that the padding is done automatically.
%
%   STRVCAT is not recommended. Use CHAR instead.
%
%   See also STRING, PAD, CHAR, STRCAT%   Copyright 1984-2016 The MathWorks, Inc.[varargin{:}] = convertStringsToChars(varargin{:});%将字符串数组转换为字符数组，其他数组不变
%convertStringsToChars，https://ww2.mathworks.cn/help/matlab/ref/convertstringstochars.htmlnuminput = nargin;
if numinput == 1 && iscellstr(varargin{1}) %iscellstr，确定输入是否为字符向量元胞数组varargin = (varargin{1});
end
% find the empty cells 
notempty = ~cellfun('isempty',varargin);
% vertically concatenate the non-empty cells.
s = char(varargin{notempty});

ind2sub 索引值转换为下标

function [v1,v2,varargout] = ind2sub(siz,ndx)
%IND2SUB Multiple subscripts from linear index.
%   IND2SUB is used to determine the equivalent subscript values
%   corresponding to a given single index into an array.
%   把矩阵中某个元素的索引值转换为下标%   [I,J] = IND2SUB(SIZ,IND) returns the arrays I and J containing the
%   equivalent row and column subscripts corresponding to the index
%   matrix IND for a matrix of size SIZ.  
%   For matrices, [I,J] = IND2SUB(SIZE(A),FIND(A>5)) returns the same
%   values as [I,J] = FIND(A>5).
%
%   [I1,I2,I3,...,In] = IND2SUB(SIZ,IND) returns N subscript arrays
%   I1,I2,..,In containing the equivalent N-D array subscripts
%   equivalent to IND for an array of size SIZ.
%
%   Class support for input IND:
%      float: double, single
%      integer: uint8, int8, uint16, int16, uint32, int32, uint64, int64
%
%   See also SUB2IND, FIND.%   Copyright 1984-2015 The MathWorks, Inc. nout = max(nargout,1);
siz = double(siz);
lensiz = length(siz);if lensiz < noutsiz = [siz ones(1,nout-lensiz)];
elseif lensiz > noutsiz = [siz(1:nout-1) prod(siz(nout:end))];
endif nout > 2k = cumprod(siz);for i = nout:-1:3,vi = rem(ndx-1, k(i-1)) + 1;vj = (ndx - vi)/k(i-1) + 1;varargout{i-2} = double(vj);ndx = vi;end
endif nout >= 2vi = rem(ndx-1, siz(1)) + 1;v2 = double((ndx - vi)/siz(1) + 1);v1 = double(vi);
else v1 = double(ndx);
end

squeeze

function b = squeeze(a)
%SQUEEZE Remove singleton dimensions.
%   B = SQUEEZE(A) returns an array B with the same elements as
%   A but with all the singleton dimensions removed.  A singleton
%   is a dimension such that size(A,dim)==1.  2-D arrays are
%   unaffected by squeeze so that row vectors remain rows.
%   返回一个数组，其元素与输入数组 A 相同，但删除了长度为 1 的维度。例如，如果 A 是 3×1×2 数组，则 squeeze(A) 返回 3×2 矩阵。%   For example,
%       squeeze(rand(2,1,3))
%   is 2-by-3.
%
%   See also SHIFTDIM.%   Copyright 1984-2010 The MathWorks, Inc. if nargin==0 error(message('MATLAB:squeeze:NotEnoughInputs')); 
endif ~ismatrix(a)siz = size(a);siz(siz==1) = []; % Remove singleton dimensions.siz = [siz ones(1,2-length(siz))]; % Make sure siz is at least 2-Db = reshape(a,siz);
elseb = a;
end

gcd（求最大公约数）

function [g,c,d] = gcd(a,b)
%GCD    Greatest common divisor.
%   G = GCD(A,B) is the greatest common divisor of corresponding elements
%   of A and B.  The arrays A and B must contain integer values and must be
%   the same size (or either can be scalar). GCD(0,0) is 0 by convention;
%   all other GCDs are positive integers.
%
%   [G,C,D] = GCD(A,B) also returns C and D so that G = A.*C + B.*D.
%   These are useful for solving Diophantine equations and computing
%   Hermite transformations.
%
%   Class support for inputs A,B:
%      float: double, single
%      integer: uint8, int8, uint16, int16, uint32, int32, uint64, int64
%
%   See also LCM.%   References:
%   Knuth, Donald, The Art of Computer Programming, Vol. 2, Addison-Wesley:
%      Reading MA, 1973. Section 4.5.2, Algorithms A and X.
%
%   Thanks to John Gilbert for the original version
%   Copyright 1984-2017 The MathWorks, Inc.if ~isequal(size(a),size(b)) && ~isscalar(a) && ~isscalar(b)error(message('MATLAB:gcd:InputSizeMismatch'))
endif ~isreal(a) || ~isequal(round(a),a) || any(isinf(a(:))) || ...~isreal(b) || ~isequal(round(b),b) || any(isinf(b(:)))error(message('MATLAB:gcd:NonIntInputs'))
endif ~isscalar(a)siz = size(a);
elsesiz = size(b);
end
a = a(:); 
b = b(:);if isinteger(a)if ~(strcmp(class(a),class(b)) || (isa(b,'double') && isscalar(b)))error(message('MATLAB:gcd:mixedIntegerTypes'))endclassin = class(a);if isa(b,'double') && (b > intmax(classin) || b < intmin(classin))error(message('MATLAB:gcd:outOfRange'));endinttype = true;
elseif isinteger(b)if ~(isa(a,'double') && isscalar(a))error(message('MATLAB:gcd:mixedIntegerTypes'))endclassin = class(b);if a > intmax(classin) || a < intmin(classin)error(message('MATLAB:gcd:outOfRange'));endinttype = true;
elseclassin = superiorfloat(a,b);largestFlint = flintmax(classin);if any(abs(a) > largestFlint) || any(abs(b) > largestFlint)warning(message('MATLAB:gcd:largestFlint'));endinttype = false;
endif nargout <= 1% intmin in signed integers requires special handlingiminIndex = [];if inttypeimin = intmin(classin);if imin < 0iminIndex = xor(a == imin, b == imin);endendu = max(abs(a),abs(b));v = min(abs(a),abs(b));u(iminIndex) = u(iminIndex)/2;vnz = v>0;while any(vnz)t = rem(u,v);u(vnz) = v(vnz);v(vnz) = t(vnz);vnz = v>0;endg = reshape(u,siz);
elseif inttypeif intmin(classin) == 0    % unsigned integers not supportederror(message('MATLAB:gcd:unsupportedType'));endendlen = prod(siz);if issparse(a) || issparse(b)u = spalloc(len,3,nnz(a)+len);elseu = zeros(len,3,classin);endu(:,1) = 1;u(:,3) = a;if issparse(b)v = spalloc(len,3,nnz(b)+len);elsev = zeros(len,3,classin);endv(:,2) = 1;v(:,3) = b;vnz = v(:,3)~=0;while any(vnz)if inttypeq = idivide(u(:,3),v(:,3));elseq = fix( u(:,3)./v(:,3));endt = u - v .* q;u(vnz,:) = v(vnz,:);v(vnz,:) = t(vnz,:);vnz = v(:,3)~=0;endg = reshape(u(:,3),siz);c = reshape(u(:,1),siz).*sign(g);d = reshape(u(:,2),siz).*sign(g);g = abs(g);% correct overflow conditions in signed integersif inttypeoverflow1 = reshape(a == intmin(classin) & b == -1, siz);overflow2 = reshape(a == -1 & b == intmin(classin), siz);g(overflow1 | overflow2) = 1;c(overflow1) = 0;d(overflow1) = -1;c(overflow2) = -1;d(overflow2) = 0;end
end

fullfile

f = fullfile(filepart1,...,filepartN) 根据指定的文件夹和文件名构建完整的文件设定。

physconst

const = physconst(name) returns the value of the physical constant const 
specified by the name argument.

typecast（在不更改基础数据的情况下转换数据类型）

Y = typecast(X,type) 将 X 的位模式转换为 type 指定的数据类型，而不更改基础数据。
X 必须为由非复数数值组成的满标量或满向量。

swapbytes（交换字节顺序）

Y = swapbytes(X) 将数组 X 中每个元素的字节排序从 little endian 转换为 big endian
（或相反）。输入数组的所有元素必须是完整的非复数数值元素。

uigetfile（选择打开文件夹）

[file,path] = uigetfile('C:\Documents\Work\*.png',...'Select an Image File')

groot（图形根对象）

Root 对象是图形对象树的根。Root 属性包含有关图形环境和图形系统的当前状态的信息。
使用圆点表示法引用特定的对象和属性。
获取主显示画面的大小
get(groot, 'ScreenSize');
使用图形根对象为其他类型的对象设置根级别的默认值。例如，将以后所有图窗的默认颜色图设置为 summer 颜色图。
set(groot,'DefaultFigureColormap',summer)

NAN（创建所有值均为 NaN 的数组）

X = NaN(sz1,...,szN) 返回由 NaN 值组成的 sz1×...×szN 数组，
其中 sz1,...,szN 指示每个维度的大小。
例如：NaN(3,4) 返回一个 3×4 的矩阵。

repmat（重复数组副本）

B = repmat(A,n) 返回一个数组，该数组在其行维度和列维度包含 A 的 n 个副本。
A 为矩阵时，B 大小为 size(A)*n。

patch（绘制一个或多个填充多边形区域）

patch(X,Y,C) 使用 X 和 Y 的元素作为每个顶点的坐标，以绘制一个或多个填充多边形区域。
patch 以您指定顶点的顺序连接这些顶点。要创建一个多边形，请将 X 和 Y 指定为向量。
要创建多个多边形，请将 X 和 Y 指定为矩阵，其中每一列对应于一个多边形。
C 决定多边形的颜色。
通过将 x 和 y 指定为两列矩阵，创建两个多边形。每一列定义其中一个多边形的坐标。
x2 = [2 5; 2 5; 8 8];
y2 = [4 0; 8 2; 4 0];
patch(x2,y2,'green')
%2、2、8是第一个多边形的x坐标；5、5、8是第二个多边形的y坐标
%4、8、4是第二个多边形的x坐标；0、2、0是第三个多边形的y坐标
%没有明显的顺时针或者逆时针

enumeration（枚举类）

%通过向类定义中添加 enumeration 代码块可创建枚举类。
%例如，WeekDays 类列举一周中的工作日。classdef WeekDaysenumerationMonday, Tuesday, Wednesday, Thursday, Fridayend
end

bitshift（移位）

noise = bitshift(AA,-4); % noise = AA/2^4

break和continue

close all;
clear all;
clc;
for ii = 1:3for jj = 1:3if ii == 1 && jj == 2break;enddisp(['ii = ',num2str(ii),'   ,jj = ',num2str(jj),'   ,aa = ',num2str(ii+jj)]);end
end
for ii = 1:3for jj = 1:3if ii == 1 && jj == 2continue;enddisp(['ii = ',num2str(ii),'   ,jj = ',num2str(jj),'   ,bb = ',num2str(ii+jj)]);end
end

结果

ii = 1   ,jj = 1   ,aa = 2
ii = 2   ,jj = 1   ,aa = 3
ii = 2   ,jj = 2   ,aa = 4
ii = 2   ,jj = 3   ,aa = 5
ii = 3   ,jj = 1   ,aa = 4
ii = 3   ,jj = 2   ,aa = 5
ii = 3   ,jj = 3   ,aa = 6
ii = 1   ,jj = 1   ,bb = 2
ii = 1   ,jj = 3   ,bb = 4
ii = 2   ,jj = 1   ,bb = 3
ii = 2   ,jj = 2   ,bb = 4
ii = 2   ,jj = 3   ,bb = 5
ii = 3   ,jj = 1   ,bb = 4
ii = 3   ,jj = 2   ,bb = 5
ii = 3   ,jj = 3   ,bb = 6

复数矩阵的.'是求转置

reshape/fftshift

classdef

classdef (Attributes) ClassName < SuperclassNameenumerationEnumNameend
end
% 例如
classdef Assigned < int32enumerationFailed        (0)succeed	    (1)end
end

isfield（确定输入是否为结构体数组字段）

确定输入是否为结构体数组字段

normrnd（生成正态随机数）

https://ww2.mathworks.cn/help/stats/normrnd.html?searchHighlight=normrnd&s_tid=srchtitle

r = normrnd(mu,sigma) 从均值参数为 mu 和标准差参数为 sigma 的正态分布中生成随机数。

r = normrnd(mu,sigma,sz1,…,szN) 生成正态随机数数组，其中 sz1,…,szN 指示每个维度的大小。

示例
r = normrnd(mu,sigma,sz) 生成正态随机数数组，其中向量 sz 指定 size®。

rand （生成均匀分布的随机数）

https://ww2.mathworks.cn/help/matlab/ref/rand.html?s_tid=doc_ta

X = rand 返回一个在区间 (0,1) 内均匀分布的随机数。

X = rand(n) 返回一个 n×n 的随机数矩阵。