Questions tagged [software]
Questions about libraries and standalone software designed or well-suited for scientific or numerical calculations.
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Most promising reduced order modeling method
Many players in the field of engineering simulation software are investing on digital twinning and reduced order modeling techniques, meaning that the field bears potential.
I was wondering if among ...
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How to convert number systems on Sharp calculator if the number has decimal points, for example 3B.254?
I would like convert decimal octal numbers on sharp EL-531TH (or any other) caclulator but when I enable the octal or any other non-decimal function, the decimal key or dot key (marked with red) is ...
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Why researchers use MATLAB based YALMIP or CasADi for MPC?
I was looking at various research papers and most of the researchers use CasADi, YALMIP, MPCTools to implement MPC. My question is "Why researchers use MATLAB based YALMIP or CasADi for MPC ...
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AMR-Capable meshing software that is not based on quad/octrees
I am looking for AMR/re-meshing software (structured grids would suffice) that is NOT based on quad-octrees, i.e., a fixed refinement rate of 2 but (ideally) something user defined, i.e., ratios of 1....
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Can I find sines or cosines of rational parts of π without using radians? If not, how do I reduce the errors caused solely by the transcendence of π?
this may be irrelevant for people who need fast code. But for me it's just the opposite -- i.e. in the specific situations when I know that the extra time allows me to make my calculations more ...
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Research profile vs coding expertise for scientific programming career
This is a question to all scientific programmers out there that have experience in academia, industry, ideally both.
Consider two figures:
Alice has earned a PhD in applied mathematics at a top 10 ...
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Issues with Simulating the Orbits of Mars and Earth using MATLAB and Runge-Kutta Method
I'm trying to simulate the orbits of Mars and Earth in MATLAB using the 4th order Runge-Kutta method for numerical integration. However, the orbits appear as straight lines rather than the expected ...
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1 dimensional simulation of gravity fails
In 1D the force of gravity does not diminish with distance however here I use 1D to mean the point mass only moves in a line in 3D space, with the other mass stationary at the origin.
I started by ...
Qni
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Best approach to simulating dynamics on networks
I have been recently getting into the field of various processes on networks. For example, stochastic processes like percolation, Ising models, various statistical-physics models; or deterministic ...
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Help with code for FDM Couette flow of two fluids on python
I'm trying to solve numerically with a python code a very simple BVP that represent the velocity field of two fluids between two plates where the driving force of the momentum transport is only for ...
Mario Riccio
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Is it normal for a genetic algorithm to not have mating phase?
I know that is possible for a genetic algorithm to not have a mating phase because some genetic algorithms use a "mutation-only" approach, where new candidate solutions are generated by ...
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Good IDE for GNU Octave?
Are there any good IDEs for working with Octave code?
I'm used to type hints and documentation preview from software like IntelliJ or VS Code. While there are syntax highlighting plugins for VSC, all ...
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Issue in implementing a cloth simulation using verlet integration
I am trying to implement a cloth simulation in c++ using verlet integration and I'm getting some odd issues that I can't seem to explain, the points in the cloth seem to fly around and have weird ...
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Geant4, simulate photon emitted into lead
I have just learned Geant4 and recently I tried to simulate photons emitted into lead. After I collected the data and figured out the transmission of photons. I found my data is bigger than the ...
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Euler integration of the three-body problem
Me and one of my colleague are trying to simulate the three-body problem with a C++ program in order to compare different integration schemes. At the moment we are trying to use the Euler's method, ...
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Implementations of the Eisenstat-trick for SSOR
Where can I find a source code for the SSOR method with Eisenstat's trick?
The original paper includes pseudo code but also seems to have minor typos. For that reason, I would be very happy to see an ...
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Software for Smith form or Hermite form of a sparse polynomial matrix
In a current research project, I have a number of matrices with coefficients in ℚ[𝑥] for which I want to understand how their rank depends on the value of the parameter 𝑥.
These matrices are:
...
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I need MATLAB or Mathematica code to solve this integral over limit 0- λ
I want the code to integrate equation(1) or (2) over the limits using mathematical or mathlab to get equation (3) as the answer of $Z$ vibrational partition function, giving the following additional ...
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Software for Feasibility Problems
I face a feasibility problem of type
$$ c_i(\boldsymbol x) \leq 0, i = 1, \dots, \mathcal{I} \\ c_e(\boldsymbol x) = 0, e = 1, \dots, \mathcal{E} $$
where $\mathcal{I} + \mathcal{E} \gg \text{dim}(\...
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Book recommendation request: A good C++ based software development book for a computational mathematician
I'm hoping that this type of question is on-topic, and I have put in a little hunting to make sure it isn't a flat out repeat. If it is either of the above, I apologize in advance.
I'm an early career ...
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How can I couple MCNP with FLUKA? To attain reactor dynamics and simulate an ADS experiment? (Under Subcritical fast system)
I'm new in Particle Physics based Computing. I want to simulate an ADS experiment (Accelerator Driven System) in subcritical fast system. I was advised to simulate the experiment with FLUKA with MCNP ...
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How can I plot a rainbow?
I'm trying to write a program that can simulate a rainbow. So far I've got figured out how to determine the change in the refractive index depending on the wavelength, the angular deviation of the ...
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Convoluted exponential gaussian probability function from Igor Pro
I am trying to figure out the exact formula for a three convoluted exponential gaussian probability function from the software Igor Pro, from my research. Unfortunately all I the closest equation from ...
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How to solve nonlinear second order ODE in Matlab? [duplicate]
I am working on simulating a car suspension system using Matlab.
Specifically, I have to derive equation of motion using the Lagrange method and then use ode 45 to solve it. However, while using ...
Luận Trần Công
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Continuum solutions for the Dirac equation in Coulomb potential - numerical codes
Following the representation used in [1, pag. 11] the solution of the Dirac equation in polar coordinates for energy $E$ is of the type:
$$ \psi_{E\kappa m}(\bf{r})= \dfrac{1}{r} \Bigg( \begin{matrix}
...
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570
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Reference request: C++ and numerical analysis book
I'm a master student with a good Numerical analysis background. I'm going to do a master thesis in the same subject, but I need to use C++ since my advisor loves it, and I also believe it's the best ...
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Diagonalization using LAPACK
Say, we have a Hamiltonian which for simplicity does not mix particle hole sectors. It is just a simple Hamiltonian in real space as shown,
$H=\sum_{ij,\sigma} A(i,j)(c_{i\sigma}^{\dagger}c_{j\sigma} +...
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Numerical minimization of the action in python
I want to find the trajectory $x(t)$ which minimizes the action $S = \int_{t_i}^{t_f} L(x(t), \dot{x}(t)) \mathrm{d}t$ numerically.
I am trying to do it by discretizing the action so it is more of a ...
murt_
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Draw magnetic field lines or vector field of a magnetic dipole - Python/Matplotlib
In the Wikipedia article on magnetic moments, subsection "Effects on environment" defines the magnetic field H of a magnetic dipole moment. Additionally the magnetic field lines of this ...
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Open-source Hexahedral meshing tools
I'm looking for an open-source automatic meshing tool or library able to generate full or dominant hexahedral mesh starting from a provided arbitrary model i.e. a surface triangular mesh stored in STL ...
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Trouble Estimating Motor Parameters with Least Squares in MATLAB
Basically, I'm trying to use Least-Squares to estimate the parameters of a DC motor.
My system can be modeled by the following matrix equation:
$$\begin{bmatrix}V_{input}(t)\\0\end{bmatrix}=\begin{...
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Solution of Coupled Differential equation for a 2d linear flow using RK4 method in python 3
I want to study the dynamics of a 2d linear flow, whose dynamical equation is- $\begin{pmatrix} \dot{x_1}\\ \dot{x_2}\\ \end{pmatrix}=\begin{pmatrix} 1 & 1\\ 4 & -2\\ \end{pmatrix}\begin{...
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How to properly calculate CPU and GPU FLOPS performance?
Problem
I'm trying to calculate CPU / GPU FLOPS performance but I'm not sure if I'm doing it correctly.
Let's say we have:
A Kaby Lake CPU (clock: 2.8 GHz, cores: 4, threads: 8)
A Pascal GPU (clock: ...
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I'm trying to add a colour to the LogicalVolume in Geant4. I get the error that fVisAttributes and visAttributes are undefined. How can I fix this?
I'm trying to add a colour to the LogicalVolume which has been renamed to TrackerLogical in Geant4. I get the error that fVisAttributes and visAttributes are undefined although I have defined them in ...
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Coroutines for ODE solvers
Are there any ODE solver packages that use coroutines and yield their results instead of functions and returning?
Briefly, a subroutine in a programming language does some computations, returns a ...
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Writing code on the CPU while developing, running it on the GPU when live - which approach?
In my simulations I am using dense matrix-vector multiplications and 2D-fft transformations quite often, for matrix sizes of 8kx8k and up. Hence, I assume that using a GPU is beneficial for speeding ...
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Is it possble to do this complex symbolic calculation with Matlab?
Sorry it's bit abrupt, but recently I am caught up in some symbolic calcualtion which is tedious and almost impossible with mere human hands, so just wondering is it possible to solve the double ...
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What guidelines should I follow for simulation software projects?
I am not sure whether this question belongs here, but I would like to give it a try and benefit from the experience of the people at scicomp.SE.
From my experience, the software quality in ...
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Manual for library Libxc
Where can I find the manual for software library Libxc for exchange-correlation functionals? Links with domain www.tddft.org don't work.
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How should errors be reported in scientific libraries?
There are many philosophies in different software engineering disciplines about how libraries should cope with errors or other exceptional conditions.
A few of the ones I've seen:
Return an error ...
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Best way of storing numerical data in a compact manner, while leaving it accessible for tools like GnuPlot?
My simulation, written in C++, generates a large amount (roughly ~500) of text files for each set of parameters I try to simulate, with four columns of ~5k double values in each file. Furthermore, to ...
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Software for parallel incomplete LU factorisation
I am looking for a software package to compute incomplete LU factorisations in parallel. Further considerations are:
The package must allow for arbitrary level-of-fill or threshold-based truncation. ...
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Software for cellular automota
I would like to do simulations using cellular automata to describe the behavior of influenza. What software do you recommend?
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Best software to do big number calculations quickly
I am trying to do some work on some math conjecture. I am testing the conjecture numbers using very large math numbers (100+ digits ). I am currently using python to test these numbers.
In the ...
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Integrating/Implementing NURBS-related calculations
Recently, I started to develop some codes that use NURBS (general things I intend to use/already using: spline generation, interpolation, grids, isolines, closest-point find, and many others), both ...
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Which free library should I use to perform cutting/clipping operation?
I have a set of points which forms a closed loop, and I want to perform cutting/clipping a 3D model using this loop. I have used VTK but in some cases, it has a "Cannot follow edges" problem.
Is ...
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Magnetostatic modelling Radia: Increasing distance between magnets a produces positive force until a certain point, beyond which force goes haywire
I have two sets of magnets. One set consists of two electromagnets (Shown below: Blue) and the other set consists of two NdFeB N40 permanent magnets. Both sets of magnets lie on the same plane. I want ...
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Help understanding this numerical surface integration technique?
I'm attempting to write a FORTRAN program that calculates the magnetic field, B, at any point outside of a bar magnet.
I'm going to use a first order euler scheme, where each side of the bar magnet ...
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Finite volume software packages
There are many software packages for the finite element method, of which the most popular are listed e.g. on Wikipedia. When it comes to the finite volume method, I'm not aware of any similarly ...
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Converting acceleration over time to velocity or speed in code
I have acceleration data from a sensor. X Y & Z.
I move the senor in the Y axis. Mostly in a straight line. So I ignore x & z.
From the sensor documentation
5.2.1 Acceleration output：
ax=((...
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