Skip to main content

Table 1 Notations of variables and their corresponding description

From: Activity-based Twitter sampling for content-based and user-centric prediction models

Notations Descriptions
N Total number of documents
M Total number of users, \(1<m<M\)
V Global vocabulary
w Word in vocabulary
\({u}_i\) ith user out of m
\({s}_u\) Sentiment score belongs to user (u)
q Aggregation window
\({y}_i\) Crime rate at time t(i)
\({\Delta }r\) Lag between a document and a target trend
\({p}_i\) A post tweeted at time t(i)
\({d}_i\) A document sampled at time t(i)
\({X}^{\langle c \rangle }\) Document term matrix of size \(N*|V|\) sparse matrix
\({X}^{\langle u \rangle }\) Document sentiment matrix of size \(N*M\) sparse matrix