To calculate the cross-correlation between two time series data sets in R, you can create a function that utilizes the built-in `ccf` (cross-correlation function) function in R. Below is a simple routine that demonstrates how to do this:
1. Load the necessary libraries (if required).
2. Define a function to calculate and plot the cross-correlation.
3. Call the function with your data sets.
Here's a complete example:
```r
# Load necessary