Arduino PROGMEM
To save RAM on your Arduino You can annotate immutable variables like lookup tables or strings with the PROGMEM keyword. The data will be stored in program memory. const dataType variableName[] PROGMEM = {data0, data1, data3…};
Data Science Overview
Questions Data Science tries to answer one of the following questions: Classification -> “Is it A or B?” Clustering -> “Are there groups which belong together?” Regression -> “How will it develop in the future?” Association -> “What is happening very often together?” There are two ways to tackle these problem domains with machine learning:…
The Essence of Machine Learning
The Essence of Machine Learning A pattern exists The pattern cannot be described mathematically We have data on this problem
SQL-Basics: Create – Read – Update – Delete
This episode is about the basic statements needed to create, read, update and delete data in a database system. It is part of my SQL-Tutorial Motivation Let’s assume we work as a data scientist for Knight Industries. We want to help the Foundation of Law and Government to keep track of our operatives. We decide…
SQL – the dark side
Sometimes your RDBMS does not allow you to do certain changes like updating a table without using a WHERE clause that uses a key column. When you are really sure what you want to do: SET SQL_SAFE_UPDATES = 0; Now the dirty brown magic can begin! Back to the SQL-Tutorial
SQL-Basics – Subqueries: Update column with values from another column
Sometimes You screw up your database design and you have redundancies i.e. your database is not normalized. If You want to correct that: Subqueries for the rescue! In our example we have two tables which contain almost the same information: CREATE TABLE installed_device (`id` int, `device` text, `info` text); INSERT INTO installed_device (`id`, `device`, `info`)…
SQL comments
You can comment your queries with — This is a comment in SQL SELECT * FROM my_table — WHERE id = 1