Publications by Pablo Casas

How to self-publish a book: Customizing Bookdown

27.08.2018

tl;dr: This post is related to How to self-publish a book: A handy list of resources. It’s centered around Bookdown and some non-standard customizations I found useful to create the Data Science Live Book. The first steps into Bookdown Amazon Kindle format Building the book Be mindful of the line width At the beginning of every ‘.Rmd’ Some...

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Sample size and class balance on model performance

05.09.2018

tl;dr: This post shows the relationship between the sample size and the accuracy in a classification model. I hope this little research I did may help you in your classification problems. An LSTM model created in Keras was used to produce the results. The metric we are tracking is categorical_accuracy (equivalent to accuracy for multi-class), whi...

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How to create a sequential model in Keras for R

16.09.2018

tl;dr: This tutorial will introduce the Deep Learning classification task with Keras. We will particularly focus on the shape of the arrays, which is one of the most common pitfalls. The topics we’ll cover are: How to do one-hot encoding Choosing the input and output shape/dimensions in the layers How to train the model How to evaluate the mod...

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How to apply a function to a matrix/tibble

25.09.2018

Scenario: we got a table of id-value, and a matrix/tibble that contains the id, and we need the labels. It may be useful when predicting the Key (or Ids) of in a classification model (like in Keras), and we need the labels as the final output. There are two interesting things: The usage of apply based on column and rows at the same time. The cre...

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Integrating R and Telegram

07.11.2018

Hi there! tl;dr: Some models (deep learning) take a long time to finish. Even some data preparation scripts. We can be notified that the process ended by Telegram sending messages from R. Get notify by Telegram bot This section is entirely based on the documentation of telegram.bot package, by Ernest Benedito. Please visit the site to get used of...

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Feature Selection using Genetic Algorithms in R

15.01.2019

This is a post about feature selection using genetic algorithms in R, in which we will do a quick review about: What are genetic algorithms? GA in ML? What does a solution look like? GA process and its operators The fitness function Genetics Algorithms in R! Try it yourself Relating concepts Animation source: “Flexible Muscle-Based Locomotion...

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New discretization method: Recursive information gain ratio maximization

13.02.2019

Hello everyone, I’m happy to share a new method to discretize variables I was working on for the last few months: Recursive discretization using gain ratio for multi-class variable tl;dr: funModeling::discretize_rgr(input, target) The problem: Need to convert a numeric variable into one categorical, considering the relationship with the target ...

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A gentle introduction to SHAP values in R

18.03.2019

Hi there! During the first meetup of argentinaR.org -an R user group- Daniel Quelali introduced us to a new model validation technique called SHAP values. This novel approach allows us to dig a little bit more in the complexity of the predictive model results, while it allows us to explore the relationships between variables for predicted case. ...

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How to use `recipes` package from `tidymodels` for one hot encoding ????

08.07.2019

Since once of the best way to learn, is to explain, I want to share with you this quick introduction to recipes package, from the tidymodels family. It can help us to automatize some data preparation tasks. The overview is: How to create a recipe How to add a step How to do the prep Getting the data with juice! Apply the prep to new data What is...

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How to use `recipes` package from `tidymodels` for one hot encoding ????

08.07.2019

Since once of the best way to learn, is to explain, I want to share with you this quick introduction to recipes package, from the tidymodels family. It can help us to automatize some data preparation tasks. The overview is: How to create a recipe How to add a step How to do the prep Getting the data with juice! Apply the prep to new data What is...

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