Matlab 使用矩阵元素作为另一个矩阵的索引

我有一个0的m×n矩阵，叫做

weightmat

---

我有一个唯一随机整数的m×k矩阵，称为

placeIn

，其中kplaceIn中的最大元素是技巧是

sub2ind

：

% First generate the row indices used for the indexing.  We'll ignore the column.
[r c] = meshgrid(1:size(placeIn, 2), 1:size(placeIn,1));

weightmat = zeros(5,10);

% Now generate an index for each (c, placeIn) pair, and set the corresponding
% element of weightmat to that value of placeIn
weightmat(sub2ind(size(weightmat), c, placeIn)) = placeIn;

---

诀窍是

sub2ind

：

% First generate the row indices used for the indexing.  We'll ignore the column.
[r c] = meshgrid(1:size(placeIn, 2), 1:size(placeIn,1));

weightmat = zeros(5,10);

% Now generate an index for each (c, placeIn) pair, and set the corresponding
% element of weightmat to that value of placeIn
weightmat(sub2ind(size(weightmat), c, placeIn)) = placeIn;

---

诀窍是

sub2ind

：

% First generate the row indices used for the indexing.  We'll ignore the column.
[r c] = meshgrid(1:size(placeIn, 2), 1:size(placeIn,1));

weightmat = zeros(5,10);

% Now generate an index for each (c, placeIn) pair, and set the corresponding
% element of weightmat to that value of placeIn
weightmat(sub2ind(size(weightmat), c, placeIn)) = placeIn;

---

诀窍是

sub2ind

：

% First generate the row indices used for the indexing.  We'll ignore the column.
[r c] = meshgrid(1:size(placeIn, 2), 1:size(placeIn,1));

weightmat = zeros(5,10);

% Now generate an index for each (c, placeIn) pair, and set the corresponding
% element of weightmat to that value of placeIn
weightmat(sub2ind(size(weightmat), c, placeIn)) = placeIn;