I think it is using the rank of |: and applying it to # https://code.jsoftware.com/wiki/Vocabulary/quotev
# b. 0 _ 1 _ |: b. 0 _ 1 _ Since they have the same rank the result would be equivalent. Cheers, bob > On Feb 10, 2020, at 10:20, Devon McCormick <[email protected]> wrote: > > Hi - recently, looking at some old code, I came across this puzzling line: > fls=. (whentry*.-.whdirs)#"|:fls > It appears I meant to do this: > fls=. (whentry*.-.whdirs)#fls > I intended the Boolean vector on the left to remove corresponding rows from > the "fls" matrix. I don't know how I came up with the unnecessarily > complex version and do not know why it works. > > Can someone explain or point me to the relevant documentation for "rank"? > > Thanks, > > Devon > -- > > Devon McCormick, CFA > > Quantitative Consultant > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
