[R] figure-definition and heatmap question

[Antje]

Hello,

I have two questions. I'd like to visualize data with a heatmap and I have the 
following testcase:

x <- rnorm(256)
nx <- x + abs(min(x))
nnx <- 255/max(nx) * nx
x <- matrix(nnx, 16, 16)
rownames(x) <- c("A","B","C","D","E","F","G","I","H","J","K","L","M","N","O","P")
par(fin=c(8.0,8.0))
cp <- colorRampPalette(c("white","springgreen","darkgreen"),space="Lab")
heatmap(x, Rowv = NA, Colv = NA, scale="none", col=cp(200))

I defined the figure region to make sure that each position is a square. But 
with these settings I get the following output (though it looks nice):
 > x <- rnorm(256)
 > nx <- x + abs(min(x))
 > nnx <- 255/max(nx) * nx
 > x <- matrix(nnx, 16, 16)
 > rownames(x) <- 
c("A","B","C","D","E","F","G","I","H","J","K","L","M","N","O","P")
 > par(fin=c(8.0,8.0))
 > cp <- colorRampPalette(c("white","springgreen","darkgreen"),space="Lab")
 > heatmap(x, Rowv = NA, Colv = NA, scale="none", col=cp(200))
	Fehler in par(op) : ungültiger Wert für den Grafikparameter "fig" spezifiziert
 > par(fin=c(8.0,8.0))
 > cp <- colorRampPalette(c("white","springgreen","darkgreen"),space="Lab")
 > heatmap(x, Rowv = NA, Colv = NA, scale="none", col=cp(200))
	Fehler in par(op) : ungültiger Wert für den Grafikparameter "fig" spezifiziert
 > par()$fig
[1]  7.267443e-04  1.305448e-02 -2.862294e-17  9.876543e-01
 > par()$fin
[1] 0.08834875 7.06790021

Why do I get this error? Why does the parameters have these strange values 
(though I set the fin parameter before...)

And another question concerning the heatmap: May I force the funtion to plot A1 
at the upper left corner instead of the lower left?

I'll be glad about any idea how to solve these problems...

Ciao,
Antje