| Article ID: | iaor19991884 |
| Country: | Brazil |
| Volume: | 16 |
| Issue: | 2 |
| Start Page Number: | 89 |
| End Page Number: | 102 |
| Publication Date: | Dec 1996 |
| Journal: | Pesquisa Operacional |
| Authors: | Gonalves M.B. |
| Keywords: | programming: nonlinear |
In this paper we present a procedure to calibrate a gravity-opportunity model for trip distribution used in transport planning. The procedure consists of determining the maximum-likelihood estimates of the parameters of the model. In order to obtain these estimates, we formulate a problem of nonlinear programming. This problem is solved with the help of the Furless equilibrium matrices method and a method of nonlinear unrestricted optimization.