>>>>> William Dunlap via R-devel <r-devel@r-project.org> >>>>> on Tue, 8 Aug 2017 11:59:45 -0700 writes:
> Should arithmetic operations work on zero-column data.frames (returning a > zero-column data.frame with the same number of rows as the data.frame > argument(s))? Currently we get: >> 1 + data.frame(row.names=c("A","B")) > Error in data.frame(value, row.names = rn, check.names = FALSE, check.rows > = FALSE) : > row names supplied are of the wrong length >> data.frame(row.names=c("A","B")) * 2 > Error in data.frame(value, row.names = rn, check.names = FALSE, check.rows > = FALSE) : > row names supplied are of the wrong length >> data.frame(row.names=c("A","B")) / data.frame(row.names=c("A","B")) > Error in data.frame(value, row.names = rn, check.names = FALSE, check.rows > = FALSE) : > row names supplied are of the wrong length > Bill Dunlap > TIBCO Software > wdunlap tibco.com Thank you, Bill. Yes, indeed, as we have the Ops.data.frame and Math.data.frame group methods (about which I have not always been so happy, but they are inheritance from S), and as the Math methods work too, we should get this boundary case working as well for the Ops. Martin Maechler ETH Zurich and R Core ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel