{smcl} {* 17jul2003}{...} {hline} help for {hi:statsbyfast}{right:manual: {hi:[R] statsby}} {right:dialog: {dialog statsby} } {hline} {title:Collect statistics for a command across a by list -- faster} {p}{cmd:statsbyfast} is a direct replacement for {cmd:statsby}. The only difference is one of speed for large panel datasets. The syntax is the same, see help {help statsby} {title:Also see} Manual: {hi:[R] statsby} {p 4 13 2} Online: help for {help statsby} {title:Author} Michael Blasnik, Boston, MA michael.blasnik@verizon.net {title:Acknowledgements/Notes} {p} The code for statsbyfast is a direct copy of {cmd:statsby} v.1.2.3 24Oct2002. Only a few lines were changed to alter the way by groups are identified -- using -in- instead of -if-. It appears that the only effect of these changes is a dramatic (nearly 10x) speed increase when working with large panel data sets. No ill side effects have been discovered.