teens girlmatlab中如何定义局部变量,matlab局部变量定义persistent persistent (表⾯意思是 持续的，连续的)
用身份证查四级准考证Define persistent variable %%声明静态变量
Syntax %% 语法
一对一小学生persistent X Y Z %%定义局部变量 X Y Z
inuitDescription 描述
其实就是定义局部静态变量的语法，变量⽣命期为全局，但是可见性在其被声明的函数内部，
persistent X Y Z defines X, Y, and Z as variables that are local to the function in which they are declared; yet their values are retained in memory between calls to the function.
定义局部静态变量X Y Z，在函数范围内声明X Y Z，它们的值局限在这个函数内。
Persistent variables are similar to global variables becau MATLAB creates permanent storage for both. They differ from global variables in that persistent variables are known only to the function in which they are declared. This prevents persistent variables from being changed by other functions or from the MATLAB command line.
增强记忆力的食物
Persistent variables(局部变量)与global variables(全局变量) 很类似，因为matlab为它们都有固定的内存。不同的是Persistent variables仅仅在声明的函数范围内识别。与其他函数的变量或MATLAB 命令⾏所区别。
Persistent variables are cleared when the M-file is cleared from memory or when the M-file is changed. To keep an M-file in memory until MATLAB quits, u mlock.
当M⽂件被从内存中清除或当M⽂件被改变时，Persistent变量被清除。要保持M⽂件在内存中，请使⽤mlock
If the persistent variable does not exist the first time you issue the persistent statement, it is initialized to the empty matrix.
如果Persistent变量在声明时没有赋值，将被初始化为空矩阵。
It is an error to declare a variable persistent if a variable with the same name exists in the current workspace.
如果在当前⼯作空间中有同名的变量存在，则声明同名的Persistent变量将会报错。
Remarks 备注
There is no function form of the persistent command (i.e., you cannot u parenthes and quote the variable names).
Matlab不允许将Persistent变量声明为函数参数。
副翼
Example 举例
This function prompts a ur to enter a directory name to u in locating one or more files. If the ur has already entered this information, and it requires no modification, they do not need to enter it again. This is becau the function stores it in a persistent variable (lastDir), and offers it as the default lection. Here is the function definition:
这个函数提⽰你输⼊⼀串字符定位⽂件。如果你已经输⼊了确切信息，就不必要再改变了。
这个函数定义了⼀个局部变量lastDir，并把默认选择赋值给它lastDir。下⾯是函数列：
function find_file(file)%%头⽂件
persistent lastDir %定义persistent variable
if impty(lastDir)
prompt = 'Enter directory: '; %初始状态为'Enter directory:
el
prompt = ['Enter directory[' lastDir ']: ']; %默认路径名
end
respon = input(prompt, 's'); %输⼊路径名
if ~impty(respon)
dirName = respon;
i can do itel
dirName = lastDir;杂七杂八的英文
end
dir(strcat(dirName, file)) %查找⽂件
lastDir = dirName; %赋值迪迪龙
Execute the function twice. The first time, it prompts you to enter the information and does not offer a default: cd(matlabroot)
find_file('is*.m')
Enter directory: toolbox/matlab/strfun/
iscellstr.m ischar.m isletter.m isspace.m isstr.m
isstrprop.m
The cond time, it does offer a default taken from the persistent variable dirName:
find_file('is*.m')
Enter directory[toolbox/matlab/strfun/]: toolbox/matlab/elmat/
impty.m isfinite.m isscalar.m
iqual.m isinf.m isvector.m
love holic
iqualwithequalnans.m isnan.m
