matlab - 如果在 Matlab 中的第一行中的特定值，如何删除列？

Question

如果我有一排

A =
     1     2     3     4     2     4     7

然后我可以删除两个

>> A(A==2)=[]
A =
     1     3     4     4     7

现在假设我有

>> A=[1,2,3,4,2,4,7; 1,2,3,4,5,6,7]
A =
     1     2     3     4     2     4     7
     1     2     3     4     5     6     7

那么如何删除顶部有两个的整个列？

Answer 1

基本索引：

A = [1,2,3,4,2,4,7; 1,2,3,4,5,6,7]
% Index those columns which have a 2 in first row
idx = A(1,:) == 2;
% Take all rows, but only column that do not have a 2 in first row
A   = A(:,~idx); % equivalent to A(:,idx) = [];