The Ljung-Box test (named for Greta M. Ljung and George E. P. Box) is a
portmanteau test for autocorrelated errors. A portmanteau test tests whether
any of a group of autocorrelations of a time series are different from zero.
The Ljung-Box statistic is better for all sample sizes including small ones.
The Box-Pierce test statistic is a simplified version
of the Ljung-Box statistic for which subsequent simulation studies have shown
The R equivalent function is Box.test.