Exercise

Creating sample data with .N

For creating test data, take advantage of data.table's handy .N object, in-place assignment, and random number generators. You can do some really cool things, like adding a configurable number of random features to a training dataset.

In this exercise, you'll write a function that adds new data to a data.table without needing the user to specify explicitly how many rows it has.

Instructions 1/3

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Create someDT, a 500-row data.table with a POSIXct column, "timestamp", starting at start_date and ending at end_date.