GNU libmatheval is a library (callable from C and Fortran) to parse and evaluate symbolic expressions input as text. It supports expressions in any number of variables of arbitrary names, decimal constants, basic unary and binary operators, and elementary mathematical functions. In addition to parsing and evaluation, libmatheval can also compute symbolic derivatives and output expressions to strings.
PFMD is a program that simulates the liquid state of a polarizable fluid by means of a dissociable potential applied in a Molecular Dynamics algorithm. Currently supported molecules are water (H2O) and MX3, where M is a metal chosen among Al, Fe, or Ga and X is a halogen among Cl, Br, or I.
GetDP is a general finite element solver using mixed elements to discretize de Rham-type complexes in one, two, and three dimensions. The main feature of GetDP is the closeness between the input data defining discrete problems (written by the user in ASCII data files) and the symbolic mathematical expressions of these problems.
PCP (Pattern Classification Program) is a machine learning program for supervised classification of patterns. It runs in interactive and batch modes, and implements the following machine learning algorithms and methods: k-means clustering, Fisher's linear discriminant, dimension reduction using Singular Value Decomposition, Principal Component Analysis, feature subset selection, Bayes error estimation, parametric classifiers (linear and quadratic), pseudo-inverse linear discriminant, k-Nearest Neighbor method, neural networks, Support Vector Machine algorithm (SVM), model selection for SVM, cross-validation, and bagging (committee) classification.
SUNDIALS (SUite of Nonlinear and DIfferential/ALgebraic equation Solvers) provides robust time integrators and nonlinear solvers that can easily be incorporated into existing simulation codes. It requires minimal information from the user, allow users to easily supply their own data structures underneath the solvers, and allows for easy incorporation of user-supplied linear solvers and preconditioners.
CFITSIO is a library of C and Fortran subroutines for reading and writing data files in the FITS (Flexible Image Transport System) data format. It simplifies the task of writing software that deals with FITS files by providing an easy to use set of high-level routines that insulate the programmer from the internal complexities of the FITS file format.
The National Space Science Data Center's (NSSDC) Common Data Format (CDF) is a self-describing data abstraction for the storage and manipulation of multidimensional data in a platform- and discipline-independent fashion. It consists of a scientific data management package (known as the "CDF Library") that allows programmers and application developers to manage and manipulate scalar, vector, and multi-dimensional data arrays.