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The TRANSREG Procedure |

This section provides information on the computational resources required to use PROC TRANSREG.

Let

- More than 56(
*q*+*r*) plus the maximum of the data matrix size, the optimal scaling work space, and the covariance matrix size bytes of array space are required. The data matrix size is 8*n*(*q*+*r*) bytes. The optimal scaling work space requires less than 8(6*n*+(*p*+*k*+2)(*p*+*k*+11)) bytes. The covariance matrix size is 4(*q*+*r*)(*q*+*r*+1) bytes. - PROC TRANSREG tries to store the original and transformed data in memory. If there is not enough memory, a utility data set is used, potentially resulting in a large increase in execution time. The amount of memory for the preceding data formulas is an underestimate of the amount of memory needed to handle most problems. These formulas give the absolute minimum amount of memory required. If a utility data set is used, and if memory can be used with perfect efficiency, then roughly the amount of memory stated previously is needed. In reality, most problems require at least two or three times the minimum.
- PROC TRANSREG sorts the data once.
The sort time is roughly proportional to (
*q*+*r*)*n*.^{3/2} - One regression analysis per iteration is required
to compute model parameters (or two canonical
correlation analyses per iteration for METHOD=CANALS).
The time required for accumulating the crossproducts
matrix is roughly proportional to
*n*(*q*+*r*)^{2}. The time required to compute the regression coefficients is roughly proportional to*q*.^{3} - Each optimal scaling is a multiple regression
problem, although some transformations are
handled with faster special-case algorithms.
The number of regressors for the optimal scaling
problems depends on the original values of the
variable and the type of transformation.
For each monotone spline transformation, an unknown
number of multiple regressions is required to find a
set of coefficients that satisfies the constraints.
The B-spline basis is generated twice for each SPLINE
and MSPLINE transformation for each iteration.
The time required to generate the B-spline
basis is roughly proportional to
*nk*.^{2}

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