Author Archives: news

Choices and example of wrapping C++ code into Python

In 2019, I started a new project on my github. This project list most popular approaches to wrap C and C++ classes into Python modules. pybind11boost-pythonswigcythoncfficppyy There are codes for C++ sources, setup.py and CMake integration example. I hope this … Continue reading

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Effectively work with Nautilus File Manager

This belongs to Research Software Engineering on Linux series   Add new file types into “Create Document” shortcut menu After adding empty or template files into “Template” folder in the user home, right click at the blank space of Nautilus … Continue reading

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Effectively work with terminal

This belongs to Research Software Engineering on Linux series   get package name for a missing command which can print the program full path for the command, useful if multiple version is installed. command_name without any options argument, if not … Continue reading

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Effectively setup multiple monitor layout at startup

This belongs to Research Software Engineering on Linux series Super+P shortcut key can bring up a menu to switch between mirror, single, multiple modes. keep Super key (windows key) pressed on, while P key can be released, use arrow key … Continue reading

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Cfd module for FreeCAD can work with external mesh file

http://www.iesensor.com/blog/wp-content/uploads/2018/12/FreeCAD_CFD_using_external_mesh.webm

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export salome mesh to FeNICS mesh

Salome installation download Salome platform 8.5 binary for Ubuntu 16.04 (64bit) Salome-meca is the combination of salome and code_aster (FEA), it is also possible to manually add the Code_saturne plugin for CFD installation extract this compressed file to a position … Continue reading

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Coupling OpenFOAM with FeniCS for multiphysis simulation (OpenFOAM workshop 13 presentation)

This is my presentation for OpenFOAM workshop 13 presentation, unfortunately, I can not attend the workshop in person. Link to my presentation PDF: OFW13-19-119__Coupling_OpenFOAM_with_FeniCS_for_multiphysis_simulation__QingfengXIA Outline of this presentation: 1. physics simulation automation 2. CFD module for FreeCAD (GUI for OpenFOAM) … Continue reading

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preCICE build and test on Ubuntu 16.04

  please read PDF version for better code highlighting   preCICE build and test on Ubuntu 16.04

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FreeCAD 0.17 + OpenFOAM CFD module now works on windows 10 WSL

after windows 10 2018 april update, it is possible to run my CFD module on FreeCAD 0.17 Limited by my time I can spend on this open source project, I will will make new feature in about half year, but … Continue reading

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I have developed several multi-physics solver based on Fenics and GUI within FreeCAD CFD workbench

This is also announced in Fenics support forum   Screenshot of FenicsSolver in FreeCAD Dear all, I have developed several multi-physics solver based on Fenics, it is hosted on github: https://github.com/qingfengxia/FenicsSolver This solver is data driven (json), instead of programming … Continue reading

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Add visual studio command prompt to windows explorer context menu

Recently relised visual studio build tool (with cmake support), enables building windows c++ project without GUI. It is essential to accelerate the testing of cross-platform program. It is convenient and decent to add Bash (WSL) and visual studio command line … Continue reading

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using cloud space as a private git repo

[answer from stackoverflow] It is absolutely possible – what you probably want to do is create a “bare” git repository in folder Y (git init –bare) and then add that file location as a remote: git remote add Y file:///path/to/Y … Continue reading

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BoundaryLayer setup for Gmsh 3D meshing

Precise control of the thickness of the first cell normal to wall, is crucial for  turbulence models like k-epsilon, k-omega. Before moving to turbulence flow simulation for CFD workbench of FreeCAD 2D meshing with boundary layer, tutorial <http://www.iesensor.com/blog/2017/05/24/gmsh_fenics_meshing/> 3D boundary … Continue reading

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from gmsh geo file to fenics mesh with subdomain and boundary facet exported

from dolfin import * import os.path from subprocess import Popen, PIPE, check_output # https://fenicsproject.org/qa/9983/setting-boundary-conditions-for-meshes-generated-by-gmsh # generete mesh by: gmsh test.geo -3 # dolfin-convert -i gmsh test.msh test.xml geo_file_content = “”” size = 1; //m meshThickness = size / 3; gridsize … Continue reading

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FreeCAD compatible Fenics mshr geometry building

Fenics geometry building API is based on CGAL, it can import CAD, but can not export CAD file like step. Here is a solution, not fully tested. This file may be further developed in github.

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solved Fenics (2016.2) cpp code compiling error on ubuntu 16.04

for any expression in Expression for Fenics 2016.2( installed from PPA ) “` expr = “”” x[2]> {} ? {}:{}”””.format(disc_zmax, lambda_p, lambda_d) print(expr) K = Expression(expr, element=V.ufl_element()) # error in compiling “` instant error log: ” — The imported target … Continue reading

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Cmake cheatsheet

#Cmake cheat sheet in markdown

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c and cpp pitfalls, mixing signed and unsigned integer, implicit conversion

1. mixing unsigned and sign int is a bad idea first of all, remember: signed int types will be implicitly converted to unsigned if sizeof(signed int types) == sizeof(unsigned int types) Google C++ coding standard, say “do not use unsigned … Continue reading

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compile c++ codes using Visual C++ Build Tools from the command prompt

Introducing the Visual Studio Build Tools “If you have installed Microsoft Visual C++ Build Tools 2015 on Windows 10, open the Start menu and choose All apps. Scroll down and open the Visual C++ Build Tools folder. Choose Visual C++ … Continue reading

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Mibox 2 install youtube and play to kodi (just as chromecast)

1. install shafa TV manager and/or ES file explorer to be enable install apk from USB/SD card http://www.shafa.com/articles/yWNpNK6erhB6Q4dO.html 2. install Kodi/XMBC apk from shafa’s file manager (in toolbox) on USB storage 3. install apk of youtube for Google TV, and … Continue reading

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