Search results for "Computational method"
showing 10 items of 30 documents
Gaussian quadrature rule for arbitrary weight function and interval
2019
Abstract A program for calculating abscissas and weights of Gaussian quadrature rules for arbitrary weight functions and intervals is reported. The program is written in Mathematica. The only requirement is that the moments of the weight function can be evaluated analytically in Mathematica. The result is a FORTRAN subroutine ready to be utilized for quadrature. Title of program: AWGQ Catalogue Id: ADVB_v1_0 Nature of problem Integration of functions. Versions of this program held in the CPC repository in Mendeley Data ADVB_v1_0; AWGQ; 10.1016/j.cpc.2004.12.010 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)
Evaluation of legendre functions of argument greater than one
2019
Abstract In this paper we present an algorithm to evaluate Legendre functions of the first and second kinds (P_v ,Q_v ) for integral and half-integral order and argument greater than one. The code is based on the calculation of the continued fraction for the Q's, the Wronskian relating P's and Q's and the application of forward recurrence relations for the P's and backward recurrence for the Q's. We also show an application of these algorithms to the evaluation of the electrostatic field due to a char... Title of program: DLEGENI, DLEGENS Catalogue Id: ADGO_v1_0 Nature of problem We include two codes in order to evaluate: 1) Legendre functions of half-integral order (subroutine DLEGENS) 2) …
Bill2d — A software package for classical two-dimensional Hamiltonian systems
2019
This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018) Abstract We present Bill2d, a modern and efficient C++ package for classical simulations of two-dimensional Hamiltonian systems. Bill2d can be used for various billiard and diffusion problems with one or more charged particles with interactions, different external potentials, an external magnetic field, periodic and open boundaries, etc. The software package can also calculate many key quantities in complex systems such as Poincaré sections, survival probabilities, and diffusion coefficients. While ai... Title of program: Bill2d Catalogue Id: AEYL_v1_0 Nature of problem Numerical propa…
Resolution of singularities for multi-loop integrals
2019
Abstract 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. Title of program: sector_decomposition Catalogue Id: AEAG_v1_0 Nature of problem Computation of divergent multi-loop integrals. Versions of this program held in the CPC repository in Mendeley Data AEAG_v1_0; sect…
A code to calculate (high order) Bessel functions based on the continued fractions method
2019
Abstract We have developed a fast code to calculate Bessel functions of integer and fractional order based on the continued fractions method. This algorithm is specially useful in the case of Bessel functions of high order because it does not require any recalculation using normalization relations. Title of program: BESSEL, SPHERICAL Catalogue Id: ACNL_v1_0 Nature of problem We include two codes in order to evaluate: a) Bessel functions of fractional order (Subroutine SPHERICAL) b) Bessel functions of integer order (Subroutine BESSEL) Versions of this program held in the CPC repository in Mendeley Data ACNL_v1_0; BESSEL, SPHERICAL; 10.1016/0010-4655(93)90062-H This program has been imported…
JASP: a program to estimate discovery and exclusion limits in prospective studies of searches
2019
Abstract This program computes the discovery and exclusion limits that can be set in prospective studies of new experiments in the search for new phenomena. It properly takes into account the different outcomes that the experiment can obtain including the possible signal and background fluctuations. The procedure gives in general more conservative limits than those obtained assuming that the experiment will obtain a number of events equal to the expected mean. The difference may be essential in those ... Title of program: JASP Catalogue Id: ADES_v1_0 Nature of problem Estimation of discovery and exclusion limits in prospective studies using Poisson statistics and properly including the expe…
Parallelization of adaptive MC integrators
2019
Abstract Monte Carlo (MC) methods for numerical integration seem to be embarrassingly parallel on first sight. When adaptive schemes are applied in order to enhance convergence however, the seemingly most natural way of replicating the whole job on each processor can potentially ruin the adaptive behaviour. Using the popular VEGAS-Algorithm as an example an economic method of semi-micro parallelization with variable grain-size is presented and contrasted with another straightforward approach of macro-... Title of program: pvegas.c Catalogue Id: ADGU_v1_0 Nature of problem Monte Carlo (MC) methods for numerical integration seem to be embarassingly parallel on first sight. When adaptive schem…
A code to evaluate prolate and oblate spheroidal harmonics
2019
Abstract We present a code to evaluate prolate (P^m _n (x), Q^m _n(x); n ≥ m, x > 1) and oblate (P^m _n (ix), Q^m _n(ix); n ≥ m, x > 0) spheroidal harmonics, that is, spherical harmonics (n and m integers) for real arguments larger than one and for purely imaginary arguments. We start from the known values (in closed form) of P^m _(m+1)and P^m ... Title of program: DPROH, DOBLH Catalogue Id: ADHD_v1_0 Nature of problem We include two codes in order to evaluate: Prolate spheroidal harmonics (subroutine DPROH) Oblate spheroidal harmonics (subroutine DOBLH) The two codes evaluate spheroidal harmonics of the first and second kinds for a given order m, from the lowest (positive) degree (n = m) t…
An exponential spline interpolation for unequally spaced data points
2019
Title of program: LSPLIN Catalogue Id: AAOW_v1_0 Nature of problem Quite often it is necessary to interpolate discrete points given in an interval (x1,xn) to some intermediate point x*epsilon(x1,xn) in such a way that one avoids spurious oscillations. Versions of this program held in the CPC repository in Mendeley Data AAOW_v1_0; LSPLIN; 10.1016/0010-4655(82)90062-5 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)
Transient Dynamics of Short Josephson Junctions under the influence of non-Gaussian Noise
2009
We investigate the effects of non-Gaussian white noise source on the transient dynamics of short Josephson junctions. The noise signal is simulated generating standard stable random variables with characteristic function described by Lévy index alpha and asymmetry parameter beta. We study the lifetime of the superconductive state as a function both of the frequency of the external driving bias current and the noise intensity for different values of index alpha. We compare our results with those obtained in the presence of Gaussian white noise. We find the presence of noise induced effects such as resonant activation and noise enhanced stability.