johnson eric seattle ericjohnson10vagov b matrices common row length unique solve uniquecbindab margin2 eric original message rhelpbouncesrprojectorg mailtorhelpbouncesrprojectorg behalf giuseppe paleologo sent wednesday august 06 2008 333 pm rhelprprojectorg subject r union columns two matrices posed following problemteaser given two matrices come elegant fast short function returns matrix nonduplicated columns matrices column order matter essence matrix equivalent unionxy x vectors could come anything nice ideas giuseppe giuseppe paleologo email paleologogmailcom aol gappy3000 skype gappy3000 gtalk paleologo mobile 9173313497 fact 2325826571 prime alternative html version deleted ______________________________________________ rhelprprojectorg mailing list httpsstatethzchmailmanlistinforhelp please read posting guide httpwwwrprojectorgpostingguidehtml provide commented minimal selfcontained reproducible code ______________________________________________ rhelprprojectorg mailing list httpsstatethzchmailmanlistinforhelp please read posting guide httpwwwrprojectorgpostingguidehtml provide commented minimal selfcontained reproducible code wed 06 aug 2008 164228 0700 r union columns two matrices