在MATLAB中清除内存中的项目

在这篇文章中，我们将讨论 “清除内存中的项目”，在MATLAB中可以使用清除操作来完成。

清除操作是用来从内存或当前活动的工作区中清除指定的项目。它是用来释放系统内存的。

语法:

clear 

clear name1 … nameN 

clear -regexp expr1 … exprN 

clear(‘a’, ‘b’, ‘c’) 

clear([‘a’ ‘b’ ‘c’]) 

clear functions 

clear mex 

clear global 

clear all 

clear keyword

其中,

clear ：这是用来删除当前工作区的所有项目。
clear name1, … nameN: 这是用来从内存中删除变量，如name1 … nameN。
clear -regexp expr1 … exprN：这是用来删除所有与所列正则表达式匹配的变量。这句话只用于删除变量。
clear(‘a’, ‘b’, ‘c’) 和 clear([‘a’ ‘b’ ‘c’])。如果指定的变量存在于当前函数的本地环境中，则用于删除其变量。
clear functions 。这仅用于清除未锁定的功能。如果一个函数被锁定或当前正在运行，它不会从内存中被清除。
clear mex:这是用来清除内存中的所有MEX文件。
clear global：这是用来清除所有全局变量的。
clear all。这是用来从内存中删除所有的变量、函数和MEX文件。
clear keyword：用于清除关键字所指示的项目。

示例 1:

% MATLAB code for removes all the
% items so its output is blank.
% Initializing some items
A = 2;
B = 4;
C = 6;
D = 8;
 
% Calling the clear operation to
% clear all the above specified items
clear
 
% Getting the remaining items
whos

这个例子将清除所有的值。

示例 2:

% MATLAB code for Clear operation
% Initializing some items
A = 2;
B = 4;
C = 6;
D = 8;
 
% Calling the clear operation to
% clear B and D items
clear B D;
 
% Getting the remaining items
whos

输出:

Variables in the current scope:
  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  =====
       A           1x1                          8  double
       C           1x1                          8  double
Total is 2 elements using 16 bytes

示例 3:

% MATLAB code for clear expression values
% Initializing some expressions
exp1 = 'ab+c';
exp2 = 'a-c';
exp3 = '+/gfg';
 
% Calling the clear operation to
% clear expression exp2
clear -regexp ^exp2;
 
% Getting the remaining expressions
whos

输出:

Variables in the current scope:
  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  =====
       exp1        1x4                          4  char
       exp3        1x5                          5  char
Total is 9 elements using 9 bytes

示例 4:

% MATLAB code for clear()
% Initializing some items
A = 2;
B = 4;
C = 6;
D = 8;
 
% Calling the clear function
% to clear items A and C
clear ('A', 'C');
 
% Again calling the clear function
% to clear D items
clear (['D']);
 
% Getting the remaining items B
whos

输出:

Variables in the current scope:
  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  =====
       B           1x1                          8  double
Total is 1 element using 8 bytes

示例 5:

% MATLAB code for clear global variable data
% Initializing some items
global A;
A = 2;
B = 4;
C = 6;
D = 8;
 
% Calling the clear function
% to clear global items only
clear global
 
% Getting the remaining items
whos

输出:

Variables in the current scope:
  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  =====
       B           1x1                          8  double
       C           1x1                          8  double
       D           1x1                          8  double
Total is 3 elements using 24 bytes

示例 6:

% MATLAB code for clear value of variable
% Initializing some items
global A;
A = 2;
B = 4;
keyword = 6;
D = 8;
 
% Calling the clear function
% to clear keyword items only
clear keyword
 
% Getting the remaining items
whos

输出:

Variables in the current scope:
  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  =====
    g  A           1x1                          8  double
       B           1x1                          8  double
       D           1x1                          8  double
Total is 3 elements using 24 bytes

示例 7:

% MATLAB code for all types of items are
% cleared so nothing is printed as output.
% Initializing some items
global A;
A = 2;
B = 4;
keyword = 6;
D = 8;
 
% Calling the clear function
% to clear all items
clear all
 
% Getting the remaining items
whos

这个例子将清除所有的值。