What describes data sets of the past compared to today's data sets?
Which command do you use to measure the strength of the relationship between two numeric variables?
Where can you find a registry of add on packages for a specific field (e.g. Machine Learning, Time Series, Econometrics) ?
If you want to convert from wide to long form with the package reshape2 you use the function:
Which package do you need to run the function 'fread'?