Towards this objective, we first generate the document's labels Λ (d) using a Bernoulli coin toss for each topic k, with a labeling prior probability Φ k , as shown in step 5.
next, we define the vector of document's labels to be λ (d)  This allows us to define a document-specific label projection matrix the i th row of L (d) has an entry of 1 in column j if and only if the i th document label λ is equal to the topic j, and zero otherwise.