Computational Resources

The CORRESP Procedure

Computational Resources

Let

$n_r & = & {number of rows in the table} \n_c & = & {number of columns in the tab... ...r of TABLES statement variables} \c & = & \max(n_r,n_c) \d & = & \min(n_r,n_c) \$

For TABLES statement input, more than

32(t+1)+8(max(2tn,(n_r+3)(n_c+3)))

bytes of array space are required.

For VAR statement input, more than

16(v+2)+8(n_r+3)(n_c+3)

bytes of array space are required.

Memory

The computational resources formulas are underestimates of the amounts of memory needed to handle most problems. If you use a utility data set, and if memory could be used with perfect efficiency, then roughly the stated amount of memory would be needed. In reality, most problems require at least two or three times the minimum.

PROC CORRESP tries to store the raw data (TABLES input) and the contingency table in memory. If there is not enough memory, a utility data set is used, potentially resulting in a large increase in execution time.

Time

The time required to perform the generalized singular value decomposition is roughly proportional to 2cd² + 5d³. Overall computation time increases with table size at a rate roughly proportional to (n_r n_c)^(3/2).

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