data analysis

R or Python, you choose!

Updated 27/08/2018 I have already briefly introduced pandas, a Python library, by comparing some of its functions to their equivalents in R. Pandas is a library that makes Python almost as convenient as R when doing data visualization and exploration from matrices and data frames (it is built on top of numpy).  It has evolved a lot these past few years as has its community of users. Although pandas is being integrated in a number of specialized packages, such as rdkit [...]

By |2018-08-28T10:18:53+00:00June 26, 2017|Categories: Data Analysis, Python, R|Tags: , |1 Comment

Create a nice looking table using R

Hi everyone, Today I will introduce formattable. This package is designed for applying formatting on vectors and data frames to make data presentation easier, richer, more flexible and hopefully convey more information. We will see how to use this package to interpret your data at a glance, with just a few lines of code (You can follow along below as well as check all the code in my git). Before going further, I will specify that this package is generally used [...]

By |2017-10-25T10:14:46+00:00March 30, 2017|Categories: Data Visualization, R|Tags: , |6 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 [...]

Standard deviation on a correlation scatter plot

I was recently asked by a colleague to provide visualization of differential gene expression computed using RPKM values (two samples, no replicates) and highlight genes that were outside the distribution by 2 standard deviations or more. As a first draft, I quickly obliged by calculating the fold change distribution, computing standard deviation and drawing lines on either side of the diagonal to obtain: This turns out to be equivalent to computing the standard deviation of the residual of a linear [...]

By |2017-04-29T17:05:35+00:00April 5, 2016|Categories: Data Visualization, R, Statistics|Tags: |0 Comments

Factorial and Log Factorial

Factorial: When you need to calculate n!, you have several solutions.  The "rush" solution: using a loop or a recursive function:  def factorial_for(n): r = 1 for i in range(2, n + 1): r *= i return(r) def factorial_rec(n): if n > 1: return(n * factorial_rec(n - 1)) else: return(1) Here, the multiplication of the numbers sequentially will create a huge number very quickly. This is good, but computers are faster when 2 small numbers (120x30240) are involved in a multiplication versus the [...]

By |2017-04-29T15:33:07+00:00February 22, 2016|Categories: Performance, Python|Tags: |0 Comments