Correlation doesn't imply causation. You've probably heard that before. It's a true statement that's important in statistical analysis—if more tall people own cats, that doesn't mean that cats cause ...

IN THE mid-1990s, an algorithm trained on hospital admission data made a surprising prediction. It said that people who presented with pneumonia were more likely to survive if they also had asthma.

The correlation function is a useful signal-analysis tool that engineers often overlook. Its formidable equation, which you have probably not thought about since your undergraduate signals and systems ...