Jens Laufer
writes about Software Development, Data Science, Entrepreneurship, Traveling and Sports

February 19, 2019 · 8 minute read

10 Lessons Learned from Scraping Websites

Valuable insights which I gained from retrieving data from many websites over the last years which I want to share with you

“Data is the new oil. It’s valuable, but if unrefined it cannot really be used. It has to be changed into gas, plastic, chemicals, etc. to create a valuable entity that drives profitable activity; so must data be broken down, analysed for it to have value.” - Clive Humby A… Read more

February 5, 2019 · 5 minute read

Missing value visualization with tidyverse in R

A short practical guide how to find and visualize missing data with ggplot2, dplyr, tidyr

Finding missing values is an important task during the Exploratory Data Analysis (EDA) . They can affect the quality of machine learning models and need to be cleaned before training models. Detecting the missing values let’s you also evaluate the quality of your data retrieval process. This… Read more

June 22, 2018 · 3 minute read

Case Study: How to find a Business Opportunity in Sports Psychology

…or how to be BOD (=Business Opportunity Detective) A few days ago I was at a beach bar with a friend who is a freelancer like me. We met a young lady working at the counter who just finished university in sports psychology. She was interviewing us about our freelancership and asked us many… Read more

June 4, 2018 · 6 minute read

Mongo DB Aggregation vs R dplyr

There are powerful options to do the processing you want: Mongo DB aggregation framework : Aggegation operations process data records results. Aggregation operations group values from multiple documents together, and can perform a variety of operations on the grouped data to return a single result.… Read more