1. the correlation of a variable with itself at different points in time or space, used in statistics and signal processing to measure how a sequence relates to a shifted version of itself.
Usage: technical term used in statistics, mathematics, and engineering; commonly abbreviated as ACF (autocorrelation function)

Examples

• The autocorrelation function helps identify patterns in time series data.
• Engineers use autocorrelation to detect periodic signals in noisy measurements.
• A high autocorrelation at lag one suggests the data points are strongly dependent on their immediate predecessors.
• The autocorrelation plot revealed a seasonal pattern in the monthly sales figures.
• Statisticians examine autocorrelation to check whether regression model assumptions have been violated.