Davide Andreazzini (Page 3)

Davide Andreazzini

Sign in Subscribe

DAGs visualization using dagre-3d

DAGs visualization using dagre-3d

Directed Acyclic Graphs are directed graphs, that have a topological ordering, a sequence of the vertices such that every edge is directed from earlier to later in the sequence. DAGs are often used in ETL processes to define pipelines for ingestion/transform of files and lately as a replacement of

Sleep-sort in javascript

Sleep-sort in javascript

Sleep sort is a joke sorting algorithm. Sleep sort spawns off one process for each argument. Each process waits for n milliseconds, then prints out n, meaning it takes 1 millisecond to print out "1", 2 millisecond to print out "2", 100 millisecond to print out

Quick and useful Docker commands and configs

Quick and useful Docker commands and configs

Here is a list of some docker snippets that I use daily. Create a tagged image from Dockerfile docker build -t tag_name /path/to/ Run a docker image in detached mode docker run -p local_port:remote_port -d tag_name Remove stopped containers docker rm $(docker ps -a

Update ssh to version 7.5p1

Update ssh to version 7.5p1

Follow the instructions to update ssh on the latest version. The process requires patching the current source, which is unfortunately not written anywhere in the open-ssh website. Package Information -Download (HTTP): http://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-7.5p1.tar.gz Download MD5 sum: 652fdc7d8392f112bef11cacf7e69e23 Download size: 1.

Random project name generator (Simple project)

Random project name generator (Simple project)

This is a small project I've done during the lunch break. https://project-name-generator.herokuapp.com/

Let's encrypt manual mode using DNS record verification

Let's encrypt manual mode using DNS record verification

Here is the procedure that I've used to create a letsencrypt certificate in manual mode using a DNS record for registration. sudo letsencrypt certonly -d example.com -d www.example.com --manual --preferred-challenges dns The procedure will guide to the creation of a DNS TXT record used to

Removing the hashbang from react-router navigation

Removing the hashbang from react-router navigation

By default, react-router add the annoying and hated hashbang to the URL, here is how to remove it. import React from 'react'; import ReactDOM from 'react-dom'; import {BrowserRouter, Route, Switch} from 'react-router-dom'; //Container import Full from './containers/Full/' //Views import Login from

Using ARIMA and Box-Jenkins methodology for time series forecast - Part 1

Using ARIMA and Box-Jenkins methodology for time series forecast - Part 1

The Box-Jenkins method, named after George Box and Gwilym Jenkins, is an approach used in time series analysis to find the best fit of a time-series model to past values of a time-series applying Autoregressive Moving Average (ARMA) and Autoregressive Integrated Moving Average (ARIMA). Approach The approach has been referred

ThreeJS rotating icosahedron with images on vertices

ThreeJS rotating icosahedron with images on vertices

Simple clone of the Stripe element @ https://stripe.com/radar I had some fun replicating the rotating icosahedron of the Stripe page, and in the end, it came out pretty good. I know that on Stripe they have created their own solid using Cinema 4d. <!DOCTYPE html> <

Principal Component Analysis

Principal Component Analysis

PCA is an algorithm used to find the principal component of data. Principal components are the directions where there is the most variance, the directions where the data is most spread out. Eigenvectors and Eigenvalues On a set of data, we can deconstruct the set into eigenvectors and eigenvalues. Every

Charge Stripe Processing Fee to the user

Charge Stripe Processing Fee to the user

Following is how I've implemented the possibility to charge the stripe fee onto the user. Unfortunately, Stripe does not offer any API endpoint to get the stripe fees for a specified country so I had to do it manually. It is not perfect nor elegant but it works.

Change Swap size on a running linux machine

Change Swap size on a running linux machine

Make all swap off sudo swapoff -a Resize the swapfile sudo dd if=/dev/zero of=/swapfile bs=1M count=1024 Make swapfile usable sudo mkswap /swapfile Make swapon again sudo swapon /swapfile

dissertation tales the proposal

Unfortunately I had to remove the proposal from the website.

Scikitlearn ML algorythm cheat sheet

Lately I've been playing with some ML projects, and this chart is really useful.

Set up Python3 dev environment Ubuntu

Here is a script that I've used to set up a python environment on Ubuntu and raspbian #Update the system sudo apt-get update sudo apt-get -y upgrade #Install python and virtualenv sudo apt-get install build-essential libssl-dev libffi-dev python-dev python3-tk python3-venv python3-pip #Create env directory tree mkdir environments cd

Mediatek watchface - pacman

This Christmas I received a mediatek smartwatch so after a couple of days, I've decided to mod it a bit, and I've started to learn how to create vxp watch faces. This is my first attempt: download pacman watchface

First react app

First react app

So it's been two days that I'm trying to figure out how React works and how to use it for my projects. I have to admit that I don't like React and I prefer to work with frameworks like Angular or Ember. I know

Linux - Freeing RAM without rebooting

Linux - Freeing RAM without rebooting

Simple command to free RAM on linux without rebooting #!/bin/bash sync; echo 1 > /proc/sys/vm/drop_caches; echo 2 > /proc/sys/vm/drop_caches; echo 3 > /proc/sys/vm/drop_caches Save into a file and set executable permission. Run the file with root privileges.

Image to Byte Array

Image to Byte Array

Here is a small fiddle that I've done to convert images to byte array. I use it to create icons for my projects with Arduino and similar. The code is a mess but the part that convert the image is pretty simple. Using the Canvas object I was

Wemos D1 Mini Pinout

Wemos D1 Mini Pinout

The Wemos D1 mini is a really cool microcontroller. It costs only £5 and provides integrated WiFi bng connectivity and 13 digital I/O and 1 analog I/O. For those struggling in find the pinout scheme here it is

Control flow with promises

Control flow with promises

Promises are very powerful and allow us to create really complex asynchronous data flows. When we want to execute tasks at the same time we can use Promise.all(), but if we want to execute tasks one after the other, we need to use a different solution. Here is an

Camera tracking with NodeJS and Arduino

Camera tracking with NodeJS and Arduino

Lately I had some fun using the Arduino micro-controller with NodeJS. One of my last project is a camera mounted on a Pan&Tilt that can track colors and even faces. Materials * Arduino UNO * Mini breadboard * 2 servos * Pan & tilt frame * A webcam * A computer This is the

Jesse James Garret's methodology for designing digital products

Jesse James Garret's methodology for designing digital products

Jesse James Garrett is an information architect based in San Francisco. Garrett authored "The Elements of User Experience", a conceptual model of user-centered design first published as a diagram in 2000 and later as a book in 2002. Although originally intended for use in web design, the Elements

Best way to install ghost

Ghost is a nice blogging platform based on ember.js and running on node.js. During the configuration of this machine I have found a lot of issues in the install steps described on the official github page. After different tries I've found that you can also install

Getting Started

Welcome to Ghost

You're live! Nice. We've put together a little post to introduce you to the Ghost editor and get you started. You can manage your content by signing in to the admin area at <your blog URL>/ghost/. When you arrive, you can select this