Question

我有一个[m,n]矩阵，我希望找到不是0的值的位置并在屏幕上打印它们。使用循环我做：

disp('4) go through C and print (i,j) where element is not 0');
[m,n] = size(C);
for i= 1:m
    for j= 1:n
        if(C(i,j) ~= 0)
            result = sprintf('Element at [%d,%d] is not 0, is %d', ...
            i, j, C(i,j));            
            disp(result);
        end
    end
end

输出是这样的：

Element at [1,1] is not 0, is 1
Element at [1,2] is not 0, is 1
Element at [1,3] is not 0, is 1
Element at [1,4] is not 0, is 1

如何使用find命令执行完全相同的操作？我尝试了下面的代码，但它产生了3个一维数组......如何关联和提取它们的输出？或者我做错了什么？

%Do the same thing with find
[i,j,k] = find(C ~= 0)

Answer 1

find函数的输出参数组织如下：

[Row of element, Column of element, Value of element]

因此，使用此命令：

[r,c,v] = find(C)

将产生3个Nx1阵列，每个阵列包含上述信息。

因此，您可以使用以下代码来实现所需，使用循环索引访问数组中的每个值。请注意，您可以使用fprintf打印带格式的文本，而不是同时使用sprintf和disp。

[r,c,v] = find(C);

for k = 1:size(r,1)        
   fprintf('Element at [%d,%d] is not 0, it is %d\n',r(k),c(k),v(k)); 
end

使用此输入矩阵：

C = [1 0 0 1;0 1 0 1;0 0 1 1]

C =

     1     0     0     1
     0     1     0     1
     0     0     1     1

我们获得以下输出：

Element at [1,1] is not 0, is 1
Element at [2,2] is not 0, is 1
Element at [3,3] is not 0, is 1
Element at [1,4] is not 0, is 1
Element at [2,4] is not 0, is 1
Element at [3,4] is not 0, is 1

使用find命令获取带有过滤器

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