A common technique when creating graphics or visual representations of data is to map a value between two scales. This is useful when working on a set of values and you need to map them to a different set of values in order to show them on a graph.
The maths involved here is essentially figuring out the relationship between the value (v) in our initial scale (x, y) and multiplying this by the maximum range of the second scale (a, b).
The PHP splat operator (...) has been available in PHP since version 5.6. When it was introduced I made note of it but have never really used it, so I thought it might be interesting to explore it a little.
Internally, the ellipsis operator in PHP is called T_ELLIPSIS, although I have heard a few different names for the operator in the past. This includes names like:
A Data Access Object (DAO) is a way of taking data out of a database or API and present it in a unified way across your application. As a design pattern this has uses in standardising how a particular bit of data is passed around, without having to resort to using arrays to accomplish the same job.
I was looking at some malfunctioning code the other day where the price was pulled out of one API service and sent to another API. The problem stemmed from the fact that the value coming out of the first API was as a string and the second API required the price in pence as an integer.
The difference in formats here meant that the number had to be converted from one format to another. During this process it was found that the value was sometimes out by a single pence.
The other day I was tasked with creating the weekly quiz for my family. I decided it would be good to do a section that would consist of 10 words that were spelled using symbols of the chemical elements. The questions would be presented as a list of element names, like this.
Barium Carbon Potassium Tungsten Argon Darmstadtium
This breaks down to the element symbols in the following way.
I was saddened to hear of the passing of the Mathematician John Horton Conway today so I decided to put together a post on his 'game of life' simulator.
This game of life, more commonly called Conway's game of life, was devised by John Conway in 1970 and is a way of modelling very simple cell population dynamics. The game takes place on a two dimensional board containing a grid of orthogonal cells. The game is technically a zero player game in that the initial setup of the game dictates the eventual evolution of the board.
One technique I find useful, especially when drawing images, is to invert a number on a scale. In PHP, coordinates in an image are drawn from the top left of the image. This means that if we want to draw from the bottom left then we need to invert the y coordinate.
The following is example PHP code that creates an image with a single, diagonal line, drawn across the middle.