(from my correspondence with Sabine Schulte im Walde)
There are multiple ways of defining sample quantiles, and SAS, SPSS and R all have different defaults. The quantile() function has a type argument that lets you choose among 9 different definitions. Perhaps unfortunately, the afl.margins data is one for which the 0.25 quantile gives different answers in all three platforms:
(from my correspondence with Sabine Schulte im Walde)
There are multiple ways of defining sample quantiles, and SAS, SPSS and R all have different defaults. The
quantile()
function has a type argument that lets you choose among 9 different definitions. Perhaps unfortunately, theafl.margins
data is one for which the 0.25 quantile gives different answers in all three platforms:relevant paper:
Hyndman, R. J. and Fan, Y. (1996) Sample quantiles in statistical packages, American Statistician 50, 361–365. doi: 10.2307/2684934.