I am implementing Gaussian input based RBM in MATLAB.
vi has dimension of 100*784, w has dimension of 784*500, sigma has dimension of 1*784.
p(h|v)= sigmoid(cj+wij*vi/sigma^2). I am getting dimensional error when I multiply w*v/sigma^2.
I have implemented it as below,
poshidprobspart = bsxfun(@rdivide,data,sigmas.^2);
poshidprobs = 1./(1 + exp(-((vishid * poshidprobspart) + repmat(hidbiases,numcases,1))));
What is causing the error in the code
在代码部分bsxfun(@rdivide,data,sigmas.^2)，您需要对齐匹配的非单件维度。也就是说，如果大小sigmas为1x784，大小data为784x500，则需要匹配784维度。您可能想要转置sigmas：
% bsxfun: 784x500 @rdivide 784x1 => 784x500
poshidprobspart = bsxfun(@rdivide,data,(sigmas.^2).');
然后poshidprobspart将是 784x500，然后可以相乘：vishid * poshidprobspart如果vishid是 100x784，则得到 100x500 矩阵。
如果numcases是 100 并且hidviases是长度为 500 的行向量，那么您的代码将运行。
它工作正常，如果我按照以下方式实施。
neghidprobspart1=bsxfun(@rdivide,negdata,sigmas.^2);
neghidprobspart2=vishid'*neghidprobspart1';
neghidprobs =1./(exp(-(neghidprobspart2'+repmat(hidbiases,numcases,1))));