# Introduction

IPOPT (Interior Point Optimizer, pronounced Eye-Pea-Opt'') is an open source software package for large-scale nonlinear optimization. It can be used to solve general nonlinear programming problems of the form
 (1) s.t. (2) (3)

where are the optimization variables (possibly with lower and upper bounds, and ), is the objective function, and are the general nonlinear constraints. The functions and can be linear or nonlinear and convex or non-convex (but should be twice continuously differentiable). The constraints, , have lower and upper bounds, and . Note that equality constraints of the form can be specified by setting .

Subsections