TiReX: Replica-exchange molecular dynamics using Tinker

We present a driver program for performing replica-exchange molecular dynamics simulations with the Tinker package. Parallelization is based on the Message Passing Interface, with every replica assigned to a separate process. The algorithm is not communication intensive, which makes the program suitable for running even on loosely coupled cluster systems. Particular attention is paid to the practical aspects of analyzing the program output.

Program summary

Program title: TiReXCatalogue identifier: AEEK_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEK_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 43 385No. of bytes in distributed program, including test data, etc.: 502 262Distribution format: tar.gzProgramming language: Fortran 90/95Computer: Most UNIX machinesOperating system: LinuxHas the code been vectorized or parallelized?: parallelized with MPIClassification: 16.13External routines: TINKER version 4.2 or 5.0, built as a libraryNature of problem: Replica-exchange molecular dynamics.Solution method: Each replica is assigned to a separate process; temperatures are swapped between replicas at regular time intervals.Running time: The sample run may take up to a few minutes.     

LIBERI: Library for numerical evaluation of electron-repulsion integrals

We provide a C library, called LIBERI, for numerical evaluation of four-center electron repulsion integrals, based on successive reduction of integral dimension by using Fourier transforms. LIBERI enables us to compute the integrals for numerically defined basis functions within ¹⁰−5 Hartree accuracy as well as their derivatives with respect to the atomic nuclear positions. Damping of the Coulomb interaction can also be imposed to take account of screening effect.

Program summary

Program title: LIBERICatalogue identifier: AEGG_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEGG_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 44 091No. of bytes in distributed program, including test data, etc.: 1 692 085Distribution format: tar.gzProgramming language: CComputer: allOperating system: any Unix-like systemRAM: 5-10 MbClassification: 7.4External routines: Lapack (http://www.netlib.org/lapack/), Blas (http://www.netlib.org/blas/), FFTW3 (http://www.fftw.org/)Nature of problem: Numerical evaluation of four-center electron-repulsion integrals.Solution method: Four-center electron-repulsion integrals are computed for given basis function set, based on successive reduction of integral dimension using Fourier transform.Running time: 0.5 sec for the demo program supplied with the package.     

The Invar tensor package

The Invar package is introduced, a fast manipulator of generic scalar polynomial expressions formed from the Riemann tensor of a four-dimensional metric-compatible connection. The package can maximally simplify any polynomial containing tensor products of up to seven Riemann tensors within seconds. It has been implemented both in Mathematica and Maple algebraic systems.

Program summary

Program title:Invar Tensor PackageCatalogue identifier:ADZK_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZK_v1_0.htmlProgram obtainable from:CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions:Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 136 240No. of bytes in distributed program, including test data, etc.:2 711 923Distribution format:tar.gzProgramming language:Mathematica and MapleComputer:Any computer running Mathematica versions 5.0 to 5.2 or Maple versions 9 and 10Operating system:Linux, Unix, Windows XPRAM:30 MbWord size:64 or 32 bitsClassification:5External routines:The Mathematica version requires the xTensor and xPerm packages. These are freely available at http://metric.iem.csic.es/Martin-Garcia/xActNature of problem:Manipulation and simplification of tensor expressions. Special attention on simplifying scalar polynomial expressions formed from the Riemann tensor on a four-dimensional metric-compatible manifold.Solution method:Algorithms of computational group theory to simplify expressions with tensors that obey permutation symmetries. Tables of syzygies of the scalar invariants of the Riemann tensor.Restrictions:The present versions do not fully address the problem of reducing differential invariants or monomials of the Riemann tensor with free indices.Running time:Less than a second to fully reduce a monomial of the Riemann tensor of degree 7 in terms of independent invariants.     

Motion4D - A library for lightrays and timelike worldlines in the theory of relativity

The Motion4D-library solves the geodesic equation as well as the parallel- and Fermi-Walker-transport in four-dimensional Lorentzian spacetimes numerically. Initial conditions are given with respect to natural local tetrads which are adapted to the symmetries or the coordinates of the spacetime. Beside some already implemented metrics like the Schwarzschild and Kerr metric, the object oriented structure of the library permits to implement other metrics or integrators in a straight forward manner.

Program summary

Program title: Motion4D-libraryCatalogue identifier: AEEX_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEX_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 150 425No. of bytes in distributed program, including test data, etc.: 5 139 407Distribution format: tar.gzProgramming language: C++Computer: All platforms with a C++ compilerOperating system: Linux, Unix, WindowsRAM: 39 MBytesClassification: 1.5External routines: Gnu Scientific Library (GSL) (http://www.gnu.org/software/gsl/)Nature of problem: Solve geodesic equation, parallel and Fermi-Walker transport in four-dimensional Lorentzian spacetimes.Solution method: Integration of ordinary differential equationsRunning time: The test runs provided with the distribution require only a few seconds to run.     

Algorithmic derivation of Dyson-Schwinger equations

We present an algorithm for the derivation of Dyson-Schwinger equations of general theories that is suitable for an implementation within a symbolic programming language. Moreover, we introduce the Mathematica package DoDSE¹ which provides such an implementation. It derives the Dyson-Schwinger equations graphically once the interactions of the theory are specified. A few examples for the application of both the algorithm and the DoDSE package are provided.

Program summary

Program title: DoDSECatalogue identifier: AECT_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECT_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 105 874No. of bytes in distributed program, including test data, etc.: 262 446Distribution format: tar.gzProgramming language: Mathematica 6 and higherComputer: all on which Mathematica is availableOperating system: all on which Mathematica is availableClassification: 11.1, 11.4, 11.5, 11.6Nature of problem: Derivation of Dyson-Schwinger equations for a theory with given interactions.Solution method: Implementation of an algorithm for the derivation of Dyson-Schwinger equations.Unusual features: The results can be plotted as Feynman diagrams in Mathematica.Running time: Less than a second to minutes for Dyson-Schwinger equations of higher vertex functions.     

A completely open source based computing system for computer generation of Fourier holograms

Computer generated holograms are usually generated using commercial software like MATLAB, MATHCAD, Mathematica, etc. This work is an approach in doing the same using freely distributed open source packages and Operating System. A Fourier hologram is generated using this method and tested for simulated and optical reconstruction. The reconstructed images are in good agreement with the objects chosen. The significance of using such a system is also discussed.

Program summary

Program title: FHOLOCatalogue identifier: AEDS_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDS_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 176 336No. of bytes in distributed program, including test data, etc.: 4 294 872Distribution format: tar.gzProgramming language: C++Computer: any X86 micro computerOperating system: Linux (Debian Etch)RAM: 512 MBClassification: 18Nature of problem: To generate a Fourier Hologram in micro computer only by using open source operating system and packages.Running time: Depends on the matrix size. 10 sec for a matrix of size 256×256.     

SMMP v. 3.0—Simulating proteins and protein interactions in Python and Fortran

We describe a revised and updated version of the program package SMMP. SMMP is an open-source FORTRAN package for molecular simulation of proteins within the standard geometry model. It is designed as a simple and inexpensive tool for researchers and students to become familiar with protein simulation techniques. SMMP 3.0 sports a revised API increasing its flexibility, an implementation of the Lund force field, multi-molecule simulations, a parallel implementation of the energy function, Python bindings, and more.

Program summary

Title of program:SMMPCatalogue identifier:ADOJ_v3_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADOJ_v3_0.htmlProgram obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandLicensing provisions:Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlProgramming language used:FORTRAN, PythonNo. of lines in distributed program, including test data, etc.:52 105No. of bytes in distributed program, including test data, etc.:599 150Distribution format:tar.gzComputer:Platform independentOperating system:OS independentRAM:2 MbytesClassification:3Does the new version supersede the previous version?:YesNature of problem:Molecular mechanics computations and Monte Carlo simulation of proteins.Solution method:Utilizes ECEPP2/3, FLEX, and Lund potentials. Includes Monte Carlo simulation algorithms for canonical, as well as for generalized ensembles.Reasons for new version:API changes and increased functionality.Summary of revisions:Added Lund potential; parameters used in subroutines are now passed as arguments; multi-molecule simulations; parallelized energy calculation for ECEPP; Python bindings.Restrictions:The consumed CPU time increases with the size of protein molecule.Running time:Depends on the size of the simulated molecule.     

A web-deployed interface for performing ab initio molecular dynamics, optimization, and electronic structure in Fireball

Fireball is an ab initio technique for fast local orbital simulations of nanotechnological, solid state, and biological systems. We have implemented a convenient interface for new users and software architects in the platform-independent Java language to access Fireball's unique and powerful capabilities. The graphical user interface can be run directly from a web server or from within a larger framework such as the Computational Science and Engineering Online (CSE-Online) environment or the Distributed Analysis of Neutron Scattering Experiments (DANSE) framework. We demonstrate its use for high-throughput electronic structure calculations and a multi-100 atom quantum molecular dynamics (MD) simulation.

Program summary

Program title: FireballUICatalogue identifier: AECF_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECF_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 279 784No. of bytes in distributed program, including test data, etc.: 12 836 145Distribution format: tar.gzProgramming language: JavaComputer: PC and workstationOperating system: The GUI will run under Windows, Mac and Linux. Executables for Mac and Linux are included in the package.RAM: 512 MBWord size: 32 or 64 bitsClassification: 4.14Nature of problem: The set up and running of many simulations (all of the same type), from the command line, is a slow process. But most research quality codes, including the ab initio tight-binding code FIREBALL, are designed to run from the command line. The desire is to have a method for quickly and efficiently setting up and running a host of simulations.Solution method: We have created a graphical user interface for use with the FIREBALL code. Once the user has created the files containing the atomic coordinates for each system that they are going to run a simulation on, the user can set up and start the computations of up to hundreds of simulations.Running time: 3 to 5 minutes on a 2 GHz Pentium IV processor.     

JuNoLo - Jülich nonlocal code for parallel post-processing evaluation of vdW-DF correlation energy

Nowadays the state of the art Density Functional Theory (DFT) codes are based on local (LDA) or semilocal (GGA) energy functionals. Recently the theory of a truly nonlocal energy functional has been developed. It has been used mostly as a post-DFT calculation approach, i.e. by applying the functional to the charge density calculated using any standard DFT code, thus obtaining a new improved value for the total energy of the system. Nonlocal calculation is computationally quite expensive and scales as N² where N is the number of points in which the density is defined, and a massively parallel calculation is welcome for a wider applicability of the new approach. In this article we present a code which accomplishes this goal.

Program summary

Program title: JuNoLoCatalogue identifier: AEFM_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFM_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 176 980No. of bytes in distributed program, including test data, etc.: 2 126 072Distribution format: tar.gzProgramming language: Fortran 90Computer: any architecture with a Fortran 90 compilerOperating system: Linux, AIXHas the code been vectorised or parallelized?: Yes, from 1 to 65536 processors may be used.RAM: depends strongly on the problem's size.Classification: 7.3External routines:• FFTW (http://www.tw.org/)• MPI (http://www.mcs.anl.gov/research/projects/mpich2/ or http://www.lam-mpi.org/)Nature of problem: Obtaining the value of the nonlocal vdW-DF energy based on the charge density distribution obtained from some Density Functional Theory code.Solution method: Numerical calculation of the double sum is implemented in a parallel F90 code. Calculation of this sum yields the required nonlocal vdW-DF energy.Unusual features: Binds to virtually any DFT program.Additional comments: Excellent parallelization features.Running time: Depends strongly on the size of the problem and the number of CPUs used.     

REACH: A program for coarse-grained biomolecular simulation

REACH (Realistic Extension Algorithm viaCovariance Hessian) is a program package for residue-scale coarse-grained biomolecular simulation. The program calculates the force constants of a residue-scale elastic network model in single-domain proteins using the variance-covariance matrix obtained from atomistic molecular dynamics simulation. Secondary-structure dependence of the force constants is integrated. The method involves self-consistent, direct mapping of atomistic simulation results onto a coarse-grained force field in an efficient automated procedure without requiring iterative fits and avoiding system dependence.

Program summary

Program title: REACHCatalogue identifier: AEDA_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDA_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 42 244No. of bytes in distributed program, including test data, etc.: 3 682 118Distribution format: tar.gzProgramming language: FORTRAN 77Computer: x86 PCOperating system: GNU/Linux, SUSE and Red HatRAM: Depends on the system size to be calculatedWord size: 32 or 64 bitsClassification: 3External routines: LAPACK, BLASNature of problem: A direct calculation of force field for residue-scale coarse-grained biomolecular simulation derived from atomistic molecular dynamics trajectory.Solution method: A variance-covariance matrix and the associated Hessian (second-derivative) matrix are calculated from an atomistic molecular dynamics trajectory of single-domain protein internal motion and the off-diagonal Hessian matrix is fitted to that of a residue-scale elastic network model. The resulting force constants for the residue pair interactions are expressed as model functions as a function of pairwise distance.Running time: Depends on the system size and the number of MD trajectory frames used. The test run provided with the distribution takes only a few seconds to execute.     

QCDMAPT: Program package for Analytic approach to QCD

A program package, which facilitates computations in the framework of Analytic approach to QCD, is developed and described in detail. The package includes both the calculated explicit expressions for relevant spectral functions up to the four-loop level and the subroutines for necessary integrals.

Program summary

Program title: QCDMAPTCatalogue identifier: AEGP_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEGP_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 2579No. of bytes in distributed program, including test data, etc.: 180 052Distribution format: tar.gzProgramming language: Maple 9 and higherComputer: Any which supports Maple 9Operating system: Any which supports Maple 9Classification: 11.1, 11.5, 11.6Nature of problem: Subroutines helping computations within Analytic approach to QCD.Solution method: A program package for Maple is provided. It includes both the explicit expressions for relevant spectral functions and the subroutines for basic integrals used in the framework of Analytic approach to QCD.Running time: Template program running time is about a minute (depends on CPU).     

Solution of few-body problems with the stochastic variational method II: Two-dimensional systems

A computational approach is presented for efficient solution of two-dimensional few-body problems, such as quantum dots or excitonic complexes, using the stochastic variational method. The computer program can be used to calculate the energies and wave functions of various two-dimensional systems.

Program summary

Program title: svm-2dCatalogue identifier: AEBE_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEBE_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 5091No. of bytes in distributed program, including test data, etc.: 130 963Distribution format: tar.gzProgramming language: Fortran 90Computer: The program should work on any system with a Fortran 90 compilerOperating system: The program should work on any system with a Fortran 90 compilerClassification: 7.3Nature of problem: Variational calculation of energies and wave functions using Correlated Gaussian basis.Solution method: Two-dimensional few-electron problems are solved by the variational method. The ground state wave function is expanded into Correlated Gaussian basis functions and the parameters of the basis states are optimized by a stochastic selection procedure. Accurate results can be obtained for 2-6 electron systems.Running time: A couple of hours for a typical system.     

JJGEN: A flexible program for generating lists of jj-coupled configuration state functions

The success of large scale relativistic multiconfiguration Dirac-Hartree-Fock calculations for atomic systems rely on judiciously chosen configuration expansions. Dependent on the atomic system as well as on the studied properties, various correlation effects need to be considered. Based on the active set approach, this program allows the user to generate general lists of jj-coupled configuration state functions to be used as input to the grasp2K multiconfiguration Dirac-Hartree-Fock package [P. Jönsson, X. He, C. Froese Fischer, I.P. Grant, Comput. Phys. Comm. (2007), in press].

Program summary

Program title: JJGENCatalogue identifier: ADZG_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZG_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 10 673No. of bytes in distributed program, including test data, etc.: 430 543Distribution format: tar.gzProgramming language: FortranComputer: Intel compatible PCOperating system: Linux, UnixWord size: 32 bitsClassification: 7.3Nature of problem: Generation of lists of jj-coupled configuration state functions to describe different electron correlation effects in many-electron atoms.Solution method: From a set of reference configurations a list of jj-coupled configuration state functions is generated by excitations to an active set of orbitals. Imposing restrictions on the allowed excitations the configuration expansion can be targeted to describe different correlation effects.Restrictions: The complexity of the cases that can be handled is entirely determined by the grasp2K package [P. Jönsson, X. He, C. Froese Fischer, I.P. Grant, Comput. Phys. Comm. (2007), in press] used for the generation of the electronic wave-functions.Running time: CPU time required to execute test cases: few seconds.     

S@M, a mathematica implementation of the spinor-helicity formalism

In this paper we present the package S@M (Spinors@Mathematica) which implements the spinor-helicity formalism in Mathematica. The package allows the use of complex-spinor algebra along with the multi-purpose features of Mathematica. The package defines the spinor objects with their basic properties along with functions to manipulate them. It also offers the possibility of evaluating the spinorial objects numerically at every computational step. The package is therefore well suited to be used in the context of on-shell technology, in particular for the evaluation of scattering amplitudes at tree- and loop-level.

Program summary

Program title: S@MCatalogue identifier: AEBF_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEBF_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 14 404No. of bytes in distributed program, including test data, etc.: 77 536Distribution format: tar.gzProgramming language: MathematicaComputer: All computers running MathematicaOperating system: Any system running MathematicaClassification: 4.4, 5, 11.1Nature of problem: Implementation of the spinor-helicity formalismSolution method: Mathematica implementationRunning time: The notebooks provided with the package take only a few seconds to run.     

Program package for multicanonical simulations of U(1) lattice gauge theory

We document our Fortran 77 code for multicanonical simulations of 4D U(1) lattice gauge theory in the neighborhood of its phase transition. This includes programs and routines for canonical simulations using biased Metropolis heatbath updating and overrelaxation, determination of multicanonical weights via a Wang-Landau recursion, and multicanonical simulations with fixed weights supplemented by overrelaxation sweeps. Measurements are performed for the action, Polyakov loops and some of their structure factors. Many features of the code transcend the particular application and are expected to be useful for other lattice gauge theory models as well as for systems in statistical physics.

Program summary

Program title: STMC_U1MUCACatalogue identifier: AEET_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEET_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 18 376No. of bytes in distributed program, including test data, etc.: 205 183Distribution format: tar.gzProgramming language: Fortran 77Computer: Any capable of compiling and executing Fortran codeOperating system: Any capable of compiling and executing Fortran codeClassification: 11.5Nature of problem: Efficient Markov chain Monte Carlo simulation of U(1) lattice gauge theory close to its phase transition. Measurements and analysis of the action per plaquette, the specific heat, Polyakov loops and their structure factors.Solution method: Multicanonical simulations with an initial Wang-Landau recursion to determine suitable weight factors. Reweighting to physical values using logarithmic coding and calculating jackknife error bars.Running time: The prepared tests runs took up to 74 minutes to execute on a 2 GHz PC.     

Solving surface structures from normal incidence X-ray standing wave data

A program is provided to determine structural parameters of atoms in or adsorbed on surfaces by refinement of atomistic models towards experimentally determined data generated by the normal incidence X-ray standing wave (NIXSW) technique. The method employs a combination of Differential Evolution Genetic Algorithms and Steepest Descent Line Minimisations to provide a fast, reliable and user friendly tool for experimentalists to interpret complex multidimensional NIXSW data sets.

Program summary

Program title: NIXSW Planewave SolverCatalogue identifier: ADZE_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZE_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 16 874No. of bytes in distributed program, including test data, etc.: 1 631 874Distribution format: tar.gzProgramming language: Borland C++ Builder 5Computer: Any Windows CompatibleOperating system: Windows 2000 and XPRAM: <10 MBClassification: 7.4Nature of problem: Using NIXSW experimental data to calculate atomic positions of adsorbates.Restrictions: Data from substrates must have cubic, tetragonal or orthorhombic crystal structures i.e. with 90° between conventional cell axes.Running time: Seconds-minutes dependant on the number of plane waves and the number of atomic sites.     

Resolution of singularities for multi-loop integrals

We report on a program for the numerical evaluation of divergent multi-loop integrals. The program is based on iterated sector decomposition. We improve the original algorithm of Binoth and Heinrich such that the program is guaranteed to terminate. The program can be used to compute numerically the Laurent expansion of divergent multi-loop integrals regulated by dimensional regularisation. The symbolic and the numerical steps of the algorithm are combined into one program.

Program summary

Program title: sector_decompositionCatalogue identifier: AEAG_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAG_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 47 506No. of bytes in distributed program, including test data, etc.: 328 485Distribution format: tar.gzProgramming language: C++Computer: allOperating system: UnixRAM: Depending on the complexity of the problemClassification: 4.4External routines: GiNaC, available from http://www.ginac.de, GNU scientific library, available from http://www.gnu.org/software/gslNature of problem: Computation of divergent multi-loop integrals.Solution method: Sector decomposition.Restrictions: Only limited by the available memory and CPU time.Running time: Depending on the complexity of the problem.     

Visual tool for estimating the fractal dimension of images

This work presents a new Visual Basic 6.0 application for estimating the fractal dimension of images, based on an optimized version of the box-counting algorithm. Following the attempt to separate the real information from “noise”, we considered also the family of all band-pass filters with the same band-width (specified as parameter). The fractal dimension can be thus represented as a function of the pixel color code. The program was used for the study of paintings cracks, as an additional tool which can help the critic to decide if an artistic work is original or not.

Program summary

Program title: Fractal Analysis v01Catalogue identifier: AEEG_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEG_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 29 690No. of bytes in distributed program, including test data, etc.: 4 967 319Distribution format: tar.gzProgramming language: MS Visual Basic 6.0Computer: PCOperating system: MS Windows 98 or laterRAM: 30MClassification: 14Nature of problem: Estimating the fractal dimension of images.Solution method: Optimized implementation of the box-counting algorithm. Use of a band-pass filter for separating the real information from “noise”. User friendly graphical interface.Restrictions: Although various file-types can be used, the application was mainly conceived for the 8-bit grayscale, windows bitmap file format.Running time: In a first approximation, the algorithm is linear.