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Exercise

The inference function

Next we’ll introduce a new function that you’ll be seeing a lot more of in the upcoming labs – a custom function that allows you to apply any statistical inference method that you’ll be learning in this course. Since this is a custom function, we need to load it first.

Writing a for loop every time you want to calculate a bootstrap interval or run a randomization test is cumbersome. This function automates the process. By default the inference() function takes 10,000 bootstrap samples (instead of the 100 you’ve taken above), creates a bootstrap distribution, and calculates the confidence interval, using the percentile method.

The inference() function is a bit on the heavy side, it may take a while to run.

Instructions
100 XP
  • Use the load() function to load the custom function inference() in the workspace. You can find it here: http://assets.datacamp.com/course/dasi/inference.Rdata.
  • Look at the code and try to figure out what the arguments mean.
  • Run the code and look at the plot it generates.