Genetic Algorithms with R and Shiny

Following on from this post, here's an application that uses a genetic algorithm to find the maximum of a complex function as the inputs to it are varied.

I've implemented this in R and Shiny and the application is hosted on shinyapps.io here. The application lets a user try to beat the computer and find the optimum by brute force alone. Needless to say, there's no chance of a human managing this in any meaningful time.

As with the previous post, the Rastrigin function is being used as the function to which the optimum inputs are to be sought. The R package GA is being used to find the optimum. Gratifyingly, hardly any code is needed; it is on GitHub here.

The progress of the genetic algorithm towards the goal can be plotted. Here's an example.

As with RapidMiner, convergence towards the optimum is quick, and it usually happens in about 30 generations.

In summary, of course R can do this, but for me the cool part is how concise the code is and by using Shiny how easy it is to show to others.

R packages and Shiny

Despite this blog's title containing RapidMiner, most of what I have been doing recently involves R. I maintain a GitHub repository and at the last count there are more than 50 R packages stored there. Most are private but a few are public.

I can't reveal the private ones but there are a couple of play repositories that I have published as Shiny applications.

The first one is the POTUS Progress Pie - originally posted as an idea on the HalfBakery - a site I visit a lot - see the original idea here and the R Shiny application here.

The second one shows a genetic algorithm finding the maximum to a complex function and again uses Shiny. Here's the application. Move the "audio 1" through "audio 4" sliders to try and maximise the score. Brute force is usually not an option so selecting the Find the Best option will show you the slider settings. Selecting the "Random Choice" button chooses a new function to maximise.

Coming up and in the spirit of mentioning RapidMiner, I will post the evolutionary process I used to help me win RapidMiner's recent contest...