We utilize this fact to make the document vector dv Dn sparse by zeroing attribute values whose absolute value is close to a threshold (specified as a parameter), which results in the Sparse Composite Document Vector SCDV Dn .
let p be percentage sparsity threshold parameter, a i the value of the i th attribute of the non-Sparse Composite Document Vector and n represent the n th document in the training set:    Flowcharts depicting the formation of wordtopics vector and Sparse Composite Document Vectors are shown in figure 1 and figure 2 respectively.