I can help you to..

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• Harvest data from different sources like APIs, SQL databases or messy Excel spreadsheets.
• Reformat and reshape data to make further analyses easier.
• Clean datasets removing outliers and abberant data.
• Create reproducible data preparation workflows
• Automatize the creation of data related reports

Example:

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• I collected tweets containing the #surf for 9 months to study how surfers use social media. I used the twitter API and made the data collection automatic thanks to a personnal webserver and a custom R script.
• I created a dashboard for a company called Terres Inovia. It is directly plugged on their SQL database and allows to access its information in real time.

Contact me

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Tell me more about your project at yan.holtz.data@gmail.com to see if we can work together.

I can help you for

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• Exploratory analysis of a dataset.
• Creation of clean and reproducible reports using R Markdown.
• Application of statistical methods on your dataset.
• Creation of custom scripts for analysing your data automatically

Example:

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• I'm the author of several scientific publications where I was in charge to explore and understand complex dataset in order to answer scientific questions.
• I recovered information about crypto currency prices on different exchanges and explored the data looking for arbitrage opportunities.

Contact me

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Tell me more about your project at yan.holtz.data@gmail.com to see if we can work together.

I can help you with:

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• Creation and review of graphs for scientific publication.
• Development of data application using R and Shiny.
• Creation of custom data visualization for the web using d3.js.
• Dashboard creation for real time data analysis.
• Visualization of geospatial data.

Example:

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• A website describing research results on mental disorders comorbidity.
• Data to viz: a decision tree leading to the most appropriate chart type for your data.
• See many more examples in the portfolio section of this website.

Contact me

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Tell me more about your project at yan.holtz.data@gmail.com to see if we can work together.

Description

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A group of researcher from the Institute of Molecular Bioscience investigated the geographic clustering of genetic variants that influence complex traits and disease risk in a sample of ~450,000 individuals from Great Britain.

I built a web application that goes in support of the paper intitled Genetic Consequences of Social Stratification in Great Britain.

The shiny application allows to visualize the geographic distribution of any trait. It allows to custom color scales, region shape and to apply a cartogram algorithm to the map. Moreover, the tool allows one to upload its own data to benefit this dataviz tool.

Read more

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The web application is available online. You can read the scientific paper on BioArXiv. The source code of the project are of course on Github.

Description

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Building and comparing genetic maps between several populations is a common task for geneticists.

We've created an online tool allowing to upload your maps and characterize and visualize them. Several interactive graphs are available with export options and more. The tool was created using R and Shiny, plus several Html widgets for interactivity.

Read more

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The web application is available online. You can read the scientific paper on Bioinformatics. The source code of the project are on Github.

Description

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Comorbidity is defined as the presence of 1 or more disorders in relation to an index disorder. I've been involved in a project with the Queensland Brain Institute (Australia) and the University of Aarhus (Denmark) to build an interactive website allowing to explore the discovered patterns of comorbidity between mental disorders.

The online tool goes with the publication in Jama Psychiatry. Several interactive graphs are available with export options and more. The tool was created using R and Shiny, plus several Html widgets for interactivity.

Read more

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The web application is available online. You can read the scientific paper on Bioinformatics. The source code of the project are on Github.

Description

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Terres Inovia is a French company carrying out applied research on oilseed plants and protein crop. It phenotypes the main varieties of 20 crop species in many locations for several traits every year. This information is stored in a massive SQL database.

I created a dashboard allowing to explore these data. It allows to quickly understand what variety performs well in what kind of environmental condition. It thus has a direct impact on advices provided to farmer in France.

The dashboard was created using R and Shiny. It requires several HTML widgets to create interactive graphs, and specific packages to interact with the database. Here is a screenshot of the welcome page of the application:

Read more

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I can't provide more information on this project for privacy reasons.

Description

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Google Scholar is a service that provides any researchers list of publication. I made a script that harvest this information on the web using R. It then take the list of all co-authors and check for each pair if they have published a paper together.

The network information is then visualized using static graphs with R, and also using interactive version thanks to d3.js

Read more

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Data mining part of the pipeline is available on github. Visualizations are used as example in my other projects: static charts in data to viz, interactive ones in the d3 graph gallery.

Description

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The GreenTech challenge is a Dataviz competition launched by the French Ministery of environment that took place in 2017. A huge dataset concerning pesticides in France has been released, and the goal was to build innovative visualizations to sensibilize and inform citizen concerning the french situation over the past 6 Years.

We decided to make a team of 4 friends and built a ShinyApp that allows to efficiently explore this dataset. The app is composed by several sheets, each targeting a specific theme. This tool should allow you to understand what happens in your neighbourhood and in the entire country. It is also studied to improve your genereal knowledge concerning pesticides.

Read more

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See the associated github repository for more information and source code of the project.

Description

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UNICS is a web app that helps you computing the standard error of allele frequency estimations of future pool-sequencing experiments based on different parameters. You can use it trough the online version and read the related publication.

Application looks like this:

Read more

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See the associated github repository for more information and source code of the project.

Description

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I created an R script that recovers all tweets containing the hashtags #surf and run it on a webserver for about 9 months. I recovered more than 400k tweets. Some of them being geolocalized for both home and current location, it is possible to deduce where surfers travel.

Here is an overview of the result:

Read more

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See the dedicated page in data-to-viz.com that tells more about this project, with explanation on how to build a connection map.