Question

是否有人知道如何在不使用内置命令的情况下将行向量[6 8 2]转换为列向量。我想在没有for循环的情况下这样做。请给我一个想法。有人问我这是家庭作业，我说不，这是我工作的一部分。我正在尝试使用hdl编码器将MATLAB代码转换为vhdl，但hdl编码器似乎不支持转置函数。

Answer 1

一些选项：

R = 1:10; %// A row vector

%// using built-in transpose
C = R';   %'// be warned this finds the complex conjugate
C = R.';  %'// Just swaps the rows and columns
C = transpose(R);    

%// Flattening with the colon operator
C = R(:); %// usually the best option as it also convert columns to columns...

%// Using reshape
C = reshape(R,[],1);

%// Using permute
C = permute(R, [2,1]);

%// Via pre-allocation
C = zeros(numel(R),1);
C(1:end) = R(1:end);

%// Or explicitly using a for loop (note that you really should pre-allocate using zeros for this method as well
C = zeros(numel(R),1); %// technically optional but has a major performance impact
for k = 1:numel(R)
    C(k,1) = R(k);  %// If you preallocated then C(k)=R(k) will work too
end

%// A silly matrix multiplication method
C = diag(ones(numel(R),1)*R)

Answer 2

您可以使用(:) 技巧

t = [1 2 3];
t(:)
ans =

 1
 2
 3

UPDATE ：您应该仅在以下情况下使用此方法：您有一个向量（不是矩阵）并且想要确保它是一个列向量。当您不知道变量具有什么类型（列，行）时，此方法很有用。

检查出来

t = [1 2 3]'; %// column vector
t(:)
ans =

 1
 2
 3

然而

A=magic(3); 
A(:)
ans =
 8
 3
 4
 1
 5
 9
 6
 7
 2

没有内置MATLAB命令的矢量转置

2 个答案: