Welcome to Yan Holtz's homepage.
I'm a data analysis and data visualisation specialist currently working as a software engineer for Datadog.
Hi, I'm Yan.
My job consists in helping companies and researchers to analyse their datasets. I am skilled for most data-science steps: data pre-processing, application of statistical methods, data visualization and results communication.
After having worked for renowned research institutes like the University of Queensland and private companies like Terres Inovia, I'm now working for Datadog as a software engineer.Publications Talks Twitter Github
Data harvesting, cleaning and reshaping. Development of automated workflows.+
Data exploration, application of statistical methods, reproducible data analysis.+
Short talks or multi-day courses on dataviz, R, ggplot2, data analytics and more.+
From Data to Viz - A classification of chart types based on input data format
July 2018 - 6 minutes read
I’m delighted to announce a new dataviz project called Data to Viz. It is a classification of chart types based on input data format. It comes in the form of a decision tree leading to a set of potentially appropriate visualizations to represent the dataset. - Read more
Pimp my RMD - A collection of tips for R Markdown
July 2018 - 2 minutes read
R markdown creates interactive reports from R code. I’ve created a document that provides a few tips I use on a daily basis to improve the appearance of my html outputs (my memory aid). This document is built using R Markdown and hosted on Github. - Read more
A classification of charts based on their input format, and a lot of tips and tricks.Visit
A collection of my favorite dataviz project in a pinterest style.Visit
Hundreds of R charts, always with reproducible code and explanations.Visit
A gallery of charts made with python, with a focus on Matplotlib and Seaborn.Visit
D3 is the ultimate tool for data visualization on the web. Tedious but limitless.Visit
Dashboard for Terres Inovia
A dashboard allowing to quickly access information in Terres Inovia database
The Como Project
Webpage describing a study of interconnection between mental disorders.
Published in JAMA Psychiatry
Visualize how all the co-authors of my previous supervisor are inter
A dataviz challenge on water pollution in France. Third price at the GreenTech Challenge.
Online tool to estimate standard error of allele frequency in pool-sequencing experiments. Published in Molecular Ecology
"[...] Yan did an absolutely brilliant job. He has multiple skills and qualities making him a great data science project member, and even leader : excellent knowledge and learning ability of diverse statistical and data management tools obviously, and a real knack for data viz."
D. Gouache - Deputy Director at Terres Inovia
"Yan always performed with outstanding skills and impressive capacity for adaptation and efficiency. His job was crucial for the publication of important results. [...] I thus highly recommend him for any work concering framing and analysis of huge data sets."
J. David - Professor at Montpellier Supagro
"Yan has taught me everything I know about data visualization!
He taught my group how to display data in clever ways, and has been responsible for our recent
interactive website related to psychiatric epidemiology.
Also, he is a super-fast and efficient bioinformatician. He has set up a pipeline to handle large genetic datasets and apply modern analytic methods to explore the genetic architecture of traits and disorders.
He is a super-bright guy – I can highly recommend him!"
John McGrath - Senior Researcher at the Queensland Brain Institute