Introduction to Linear Regression

A data scientist's first goal is to find underlying relations within the variables of a dataset. Several statistical and machine learning methods can be used to discover such relations. Once uncovered, this information can be applied to everyday problems. For example, in clinical medicine, a predictive model based on clinical data can help clinicians guide a patient's treatment by offering insights that might not have otherwise been taken into account. Simple linear regression One of the most basic methods available to [...]

Logistic regression and GTEx

Working with all sorts of data, it happens sometimes that we want to predict the value of a variable which is not numerical. For those cases, a logistic regression is appropriate. It is similar to a linear regression except that it deals with the fact that the dependent variable is categorical. Here is the formula for the linear regression, where we want to estimate the parameters beta (coefficients) that fit best our data : \begin{equation} Y_i = \beta_0 + \beta_1 X_i [...]

By | January 27, 2017|Categories: Bioinformatics, Data Analysis, Python|0 Comments

SNP Filtering with pyGeno

Looking over the contents of our growing blog (good job guys !), it occured to me that we had not yet posted an article pertaining to the fantastic (and homegrown !) bioinformatics resource that is pyGeno. It turns out I need to use pyGeno to generate data and it's also my turn to write a blog post, how convenient ! I'll focus the article on writing a SNP filter, which can be a bit surprising the first time you try [...]

By | December 9, 2016|Categories: Bioinformatics, Python|0 Comments

Pivoting tables : from long to wide

As bioinformaticians, we often have to work with data that are not formatted the way we would need them to be. One case we might encounter is receiving data in a "long" format instead of receiving them in a more familiar "wide" format. For those of you familiar with the ggplot R package, you know this format very well. It's the format required by ggplot to produce its nice graphs. Long genes samples expression 1 BAD S01 7.525395 2 BAD [...]

By | November 14, 2016|Categories: Python, R|0 Comments

Implementing a “Siamese” Neural Network with Mariana 1.0

Mariana was previously introduced in this blog by Geneviève in her May post Machine learning in life science. The Mariana codebase is currently standing on github at the third release candidate before the launch of the stable 1.0 release. This new version incorporates a large refactorization effort as well as many new features (a complete list of the changes found in the 1.0 version can be found in the changelog). I am taking this opportunity to present here a small tutorial on extending the [...]

By | November 7, 2016|Categories: Computer science, Data Analysis, Machine learning, Python|0 Comments