Informatique

  • Sauvegarde de l’agenda d’Owncloud/Nextcloud

    Suite, notamment, à mon passage d’Android à CyanogenMod, j’ai choisi de migrer mon agenda de Google à Owncloud. Une fois les modifications faites, sur le serveur et sur mon smartphone, il reste la question de la sauvegarde de l’agenda. Je vais expliquer dans ce billet comment on peut: Faire une sauvegarde automatique de l’agenda (chaque…

  • Lenovo T470s, Linux, wifi/ethernet and other problems

    It is often tricky to buy a recent computer and to install Linux on it. Here are a few problem I ran into when installing Linux Mint 18.1 on my T470s Unable to install GRUB Solution: Do not forget to create an EFI partition. Wifi & ethernet don’t work You can manually install a more…

  • A first project with Spark, Java, Maven and Eclipse

    The goal of this example is to make a small Java app which uses Spark to count the number of lines of a text file, or lines which contain some given word. We will work with Spark 2.1.0 and I suppose that the following are installed: Maven 3 Eclipse Spark (note: you don’t really need…

  • Linearization of a (sparse) symmetric matrix

    The post is here: https://math.rgug.ch/2016/01/26/linearization-of-a-sparse-symmetric-matrix/ The post is here: https://math.rgug.ch/2016/01/26/linearization-of-a-sparse-symmetric-matrix/

  • Netflix on Ubuntu/Linux Mint

    To install the Netflix app on Ubuntu, type the following commands in a terminal: I strongly suggest that you first launch Netflix via the terminal. If you get the error « Unable to test extended attributes at location ‘/home/username/.wine-browser’. », then you can correct the problem with the command: (Replace « USERNAME », twice, by your username). If nothing…

  • Using PARI/GP in C++

    I wanted to use PARI/GP in a C++ code and be able to compile the project with CMake. Installing the library On some distributions, there is a package for the PARI library. Ubuntu & co: libpari-dev Fedora: pari-devel If this does not work, you can install the library manually: Download the latest version of the…

  • Convert PDF to HTML with pdf2htmlEX on Ubuntu/Mint/…

    I just discovered pdf2htmlEX which is a program to covert PDF files to HTML. The result is pretty nice as shown here: https://github.com/coolwanglu/pdf2htmlEX Building pdf2htmlEX on Ubuntu/Mint is not so easy if one has not the last version of Ubuntu (for example if your are on the previous LTS). Here are the main steps. Add…

  • Polynomial long division in C++

    I needed a function to perform polynomial division in C++. The polynomials are stored in vector< int >: a polynomial is represented by the vector Input of the function: vector< int >& iNumerator : the dividend (paramater by reference!) const vector< int >& iDenominator : the divisor Output: If iNumerator is divisible by iDenominator, the…

  • Inkscape – Changer la couleur des markers

    Si vous utilisez Inkscape et que vous voulez changer la couleurs des markers (par exemple si vous voulez que l’intérieur des dot soient blancs, comme pour le graphe de Coxeter ci-dessous), vous pouvez utiliser l’extension Markers Strokepaint, qui a été développée par Aaron Spike et Nicolas Dufour. Installation Télécharger l’archive suivante: rgug.ch/hostfiles/markers_strokepaint-new.tar.gz Copier les deux…

  • C++ et MySQL

    J’ai besoin de me connecter à une base MySQL (hébergée en local) depuis un programme en C++, depuis Ubuntu. J’ai jamais vraiment oser tenter l’expérience car il me semblait que c’était compliqué. Une fois les bonnes informations trouvées ce n’est en fait pas trop difficile. Installation des librairies Sous Ubuntu et dérivés, il suffit de…

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