ALGORITHM 1: THREE-POINT RATIONAL FUNCTION INTERPOLATION FOR CALIBRATING GRAVITY MODELS
The purpose of this subroutine is to calibrate singly or doubly constrained gravity models by adjusting the impedance parameter beta using a three-point rational function to ensure that the observed and model mean trip costs are within a prespecified level of accuracy. The procedure adopted is outlined with a brief discussion of the underlying theory. /TRRL/
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Corporate Authors:
Pion Limited
207 Brondesburg Park
London NW2 5JN, England -
Authors:
- WILLIAMS, I N
- Publication Date: 1977-2
Language
- English
Media Info
- Features: References;
- Pagination: p. 215-221
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Serial:
- Environment and Planning
- Volume: 9
- Issue Number: 2
- Publisher: Pion Limited
Subject/Index Terms
- TRT Terms: Calibration; Computer programs; Costs; Gravity models; Interpolation; Mathematical analysis; Mathematical models; Rational formula (Hydraulics); Travel; Travel budgets; Travel costs
- Identifier Terms: FORTRAN (Computer program language)
- Old TRIS Terms: Rational formula
- ITRD Terms: 6471: Analysis (math); 6171: Calibration; 224: Cost; 8616: Fortran; 690: Gravity model; 698: Journey; 8645: Software
- Subject Areas: Finance; Highways; Operations and Traffic Management; I71: Traffic Theory;
Filing Info
- Accession Number: 00157486
- Record Type: Publication
- Source Agency: Transport and Road Research Laboratory (TRRL)
- Report/Paper Numbers: Analytic
- Files: ITRD, TRIS
- Created Date: Dec 8 1977 12:00AM