The LGO solver system integrates a suite of efficient global and local scope optimization strategies. LGO can handle complex nonlinear models under ‘minimal’ (continuity) assumptions. The LGO implementation linked to the GAMS modeling environment has several new features, and improved overall functionality. In this article we review the solver options and the usage of GAMS/LGO. We also present ...

Propensity score matching is often used in observational studies to create treatment and control groups with similar distributions of observed covariates. Typically, propensity scores are estimated using logistic regressions that assume linearity between the logistic link and the predictors. We evaluate the use of generalized additive models (GAMs) for estimating propensity scores. We compare l...

This document describes an implementation of a Column Generation algorithm using GAMS. The well-known cutting stock problem is used as an example.

Generalized additive models (GAMs) are a generalization of generalized linear models (GLMs) and constitute a powerful technique which has successfully proven its ability to capture nonlinear relationships between explanatory variables and a response variable in many domains. In this paper, GAMs are proposed as base classifiers for ensemble learning. Three alternative ensemble strategies for bin...

An important statistical development of the last 30 years has been the advance in regression analysis provided by generalized linear models (GLMs) and generalized additive models (GAMs). Here we introduce a series of papers prepared within the framework of an international workshop entitled: Advances in GLMs /GAMs modeling: from species distribution to environmental management , held in Riedera...

This paper discusses the special characteristics and needs of software repositories and describes how these needs have been met by some existing repositories. These repositories include Netlib, the National HPCC Software Exchange, and the GAMS Virtual Repository. We also describe some systems that provide on-line access to various types of scienti c data. Finally, we outline a proposal for inte...

We describe Pyomo, an open source software package for modeling and solving mathematical programs in Python. Pyomo can be used to define abstract and concrete problems, create problem instances, and solve these instances with standard open-source and commercial solvers. Pyomo provides a capability that is commonly associated with algebraic modeling languages such as AMPL, AIMMS, and GAMS. In co...

The paper discusses the role of Graphical User Interfaces in economic modelling and specifically the development of a new Graphical User Interface Generator for applications realized in GAMS (General Algebraic Modelling System), a widely used Algebraic Modelling Language for (bio-)economic simulation models. It motivates the development of GGIG (Gams Graphical Interface Generator) by reviewing ...