NYC-WTC_000187725

NYC 9/11 Public Portal Document

134 Table 5.6 Computational Time on the SUN Sparc Station Using Various Starting Points (in Seconds)

Rents Rents Rents Rents Equil. Within Within Within Uniformly point z, • 10% 30% 5a% Zero of Eq. of Eq. of Eq. (*) (*) (*)

Reading data I and 230 231 230 230 231 initial comps. Housing equil. 9 21 46 635+ 639 + (itera­ (1) (3) (7) (99+) (99 + ) tions) Commercial equil. and 169 169 170 output computation

(*) : Rents are randomized within the indicated band around the equilibrium point. Note : Above computations are based on the empirically based New York Model [463 employment 2ones(i=463);463 residence zones(j=463); 3 housing types (k=3) ;5 commuting modes (m=5) ;52 shopping zones (1=52) ;2 shopping modes(n=2)]. The model's housing market part has 847 equations and the commercial equilibrium part has 46 equations. The convergence tolerance is 0.5% of the equilibrium rents. Tables 5.6 and 5.7 are identical to Tables 5.4 and 5.5 and show the corresponding running times on the SUN. An iteration now takes about 7 seconds or a little more than twice what it takes on the CRAY. Typically, an entire run takes somewhat more than 408 seconds (close to 7 minutes) or 2.8 times the amount of time it takes on the CRAY, provided that a reasonable starting point is used.

Training and Software Requirements The calibration and simulation procedures rely on the knowledge of the FORTRAN programming language., This, together with some experience in handling computers and computer programs should be sufficient in operating the model. Such operations includes recalibrating the model with updated data, as well as doing simulations with the recalibrated model.

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NYC-WTC_000187865