1 Preface

As discussed above, each language has its strengths and weaknesses. In our opinion, data science is definitely a strength of Julia. At the same time, all three of us used data science tools in our day to day life. And, probably, you want to use data science too! That is why this book has a focus on data science.

Data is abundant and will be even more so in the near future. A report from late 2012 concluded that, from 2005 to 2020, the amount of data stored digitally will grow by a factor of 300, from 130 exabytes to a whopping 40,000 exabytes (Gantz & Reinsel, 2012). This is equal to 40 trillion gigabytes and, to put it into perspective, more than 5.2 terabytes for every living human currently on this planet! In 2020, on average, every person created 1.7 MB of data per second (). A recent report predicted that almost two thirds (65%) of national GDPs will have undergone digitization by 2022 (Fitzgerald et al., 2020).