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4. Performance on Hypertext Matrices

In this section, examples of the reduction in envelope size ( ) and bandwidth () for the test collection of hypertext matrices listed in Table 3 are provided. Execution times (in elapsed CPU seconds) for the symbolic (RCM) and spectral (Fiedler and Correspondence Analysis) on a Sun SPARCstation 20 (50 MHz) are also provided. The notation CACS(i) and CANC(i) is used to represent the cases when Correspondence Analysis (see Section 3.5) is used with and without distances (see Equation (6)), respectively, for the i-th largest pair of principal axes. With CANC(1), for example, and (i.e., no weighting) so that in Equation (7). In this case, row and column permutations are solely determined by the left and right singular vectors of A (, ) corresponding to the largest singular value .

Michael W. Berry (
Mon Jan 29 14:30:24 EST 1996