对非数值型数据使用`bsxfun`

Question

对于非数值型数据，是否有bsxfun等效项？

例如，我想要比较存储在两个cell-array中的所有字符串对：

>> a = {'aa', 'bb', 'cc'};
>> b = {'dd', 'aa'};
>> bsxfun( @strcmp, a, b' ); % not working for cells :-(

Answer 1

我喜欢Rody's solution，但你也可以这样做：

ia=(1:length(a)).'; ib=1:length(b);
a=a(:);
bsxfun(@(ii,jj) strcmp(  a(ii),b(jj) )  ,ia, ib);

Answer 2

怎么样

[str,ia,ib] = intersect(a,b)

Answer 3

正如错误消息所说，广播只适用于数值类型。以下是其他可能的替代方案：

a = {'aa', 'bb', 'cc'};
b = {'dd'; 'aa'};

%# obviously doesnt work
%#bsxfun(@strcmp, a, b)

%# do the singleton expansion ourselves
strcmp(repmat(a,size(b)), repmat(b,size(a)))

%# if you dislike REPMAT, we can use Tony's trick
strcmp(a(ones(size(b)),:), b(:,ones(size(a))))

%# we could also use CELLFUN
cell2mat(cellfun(@(s)strcmp(a,s), b, 'UniformOutput',false))