1. A method of comparing a unit of streaming text data to an existing document collection, comprising: constructing a term-by-document matrix of the existing document collection; decomposing the term-by-document matrix into a term basis matrix, a weights matrix, and a document basis matrix; determining a multidimensional term subspace of the term basis matrix; computing a vector representation of the unit of streaming text data; transforming the vector representation into a projection into the predetermined multidimensional term subspace; calculating a relationship value indicative of a relationship between the vector representation and the predetermined multidimensional term subspace in real-time, wherein the relationship value is a residual vector that quantifies the difference between the vector representation of the streaming text data document and the subspace representing the original document collection; and appending the projection of the unit of streaming text data to the existing document collection represented by the predetermined multidimensional term subspace, the existing document collection being represented by a quantity of vectors corresponding to an equivalent quantity of documents in the existing document collection, the appending of the projection of the streaming text data to the existing document collection being performed without determining a new multidimensional term subspace and without adding additional terms not originally included in the term basis matrix, the appending being performed when it is determined that a relationship exists between the streaming text data and the predetermined multidimensional term subspace, wherein the relationship exists when the residual vector is less than a threshold.