Uwe Ligges suggested I post this on R-bugs as a wishlist item with a
proposed patch. R considers zero-length arguments to segments() to be
an error. I would like R to allow this and to return without an
error. It occurs naturally in settings like
valid <- c(FALSE, FALSE, FALSE)
segments(x0[valid], y0[valid], x1[valid], y1[valid])
For what it may be worth, S-Plus does not consider zero-length
arguments to segments() be an error.
plot(1:10)
segments(1,1,10,10,col='green')
segments(numeric(0), numeric(0), numeric(0), numeric(0), col='green')
Error in segments(x0, y0, x1, y1, col = col, lty = lty, lwd = lwd, ...) :
invalid first argument
segments.proposal <-
function (x0, y0, x1, y1, col = par("fg"), lty = par("lty"),
lwd = par("lwd"), ...) {
if (length(x0)==0 && length(y0)==0 && length(x1)==0 && length(y1)==0)
return(invisible(NULL))
.Internal(segments(x0, y0, x1, y1, col = col, lty = lty, lwd = lwd, ...))
}
segments.proposal(numeric(0), numeric(0), numeric(0), numeric(0), col='green')
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
