R devel - Mar 2008 - [patch] add=TRUE in plot.default()

Hi all,

As long as I've used R, add=TRUE hasn't worked in contexts like this:

	f <- function(x) x^2
	X <- seq(0, 1, by=1/4)
	plot(f, col="blue")
	plot(X, f(X), col="red", type="l", add=TRUE)

I attached a fix for version 2.6.2.

Cheers,
Andrew

-------------- next part --------------
diff --git a/src/library/graphics/R/plot.R b/src/library/graphics/R/plot.R
index 233b11e..ad3529e 100644
--- a/src/library/graphics/R/plot.R
+++ b/src/library/graphics/R/plot.R
@@ -46,16 +46,24 @@ plot.default <-
     function(x, y = NULL, type = "p", xlim = NULL, ylim = NULL,
              log = "", main = NULL, sub = NULL, xlab = NULL, ylab =
NULL,
              ann = par("ann"), axes = TRUE, frame.plot = axes,
-             panel.first = NULL, panel.last = NULL, asp = NA, ...)
+             panel.first = NULL, panel.last = NULL, asp = NA, add=FALSE, ...)
 {
+    xlabel <- if (!missing(x)) deparse(substitute(x))
+    ylabel <- if (!missing(y)) deparse(substitute(y))
+    if (add) {
+	log <- paste(ifelse(unlist(par("xlog", "ylog")),
c("x", "y"), ""),
+		     collapse="")
+	xy <- xy.coords(x, y, xlabel, ylabel, log=log)
+	plot.xy(xy, type, ...)
+	return(invisible())
+    }
+
     ## These col, bg, pch, cex can be vectors, so exclude them
     ## Also, axis and box accept some of these
     localAxis <- function(..., col, bg, pch, cex, lty, lwd) Axis(...)
     localBox <- function(..., col, bg, pch, cex, lty, lwd) box(...)
     localWindow <- function(..., col, bg, pch, cex, lty, lwd)
plot.window(...)
     localTitle <- function(..., col, bg, pch, cex, lty, lwd) title(...)
-    xlabel <- if (!missing(x)) deparse(substitute(x))
-    ylabel <- if (!missing(y)) deparse(substitute(y))
     xy <- xy.coords(x, y, xlabel, ylabel, log)
     xlab <- if (is.null(xlab)) xy$xlab else xlab
     ylab <- if (is.null(ylab)) xy$ylab else ylab

I think you can use par(new = T) here:

f <- function(x) x^2
X <- seq(0, 1, by=1/4)
plot(f, col="blue")
par(new = T)
plot(X, f(X), col="red", type="l", xlab="",
ylab="")

On 09/03/2008, Andrew Clausen <clausen at econ.upenn.edu>
wrote:
> Hi all,
>
> As long as I've used R, add=TRUE hasn't worked in contexts like
this:
>
> 	f <- function(x) x^2
> 	X <- seq(0, 1, by=1/4)
> 	plot(f, col="blue")
> 	plot(X, f(X), col="red", type="l", add=TRUE)
>
> I attached a fix for version 2.6.2.
>
> Cheers,
> Andrew
>
>

-- 
Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O

On 08/03/2008 10:11 PM, Andrew Clausen wrote:
> Hi all,
> 
> As long as I've used R, add=TRUE hasn't worked in contexts like
this:
> 
> 	f <- function(x) x^2
> 	X <- seq(0, 1, by=1/4)
> 	plot(f, col="blue")
> 	plot(X, f(X), col="red", type="l", add=TRUE)
> 
> I attached a fix for version 2.6.2.
It has never been claimed that it would work, and as far as I can see, 
it doesn't make anything easier:  the last line could be replaced by

lines(X, f(X), col="red")

for more clarity from less typing.  So why would you want add=TRUE in 
plot.default?

Duncan Murdoch