upside down image/data

rm(list=ls(all=TRUE))
graphics.off()
# make a test matrix:
nr<- 3
nc<- 4
# the data:
( m<- matrix((1:(nr*nc)), nr, nc) )
     [,1] [,2] [,3] [,4]
[1,]    1    4    7   10
[2,]    2    5    8   11
[3,]    3    6    9   12

# the way that levelplot (and image) displays the data:
t(m)[dim(t(m))[1]:1, ]
     [,1] [,2] [,3]
[1,]   10   11   12
[2,]    7    8    9
[3,]    4    5    6
[4,]    1    2    3

# undo what levelplot does by performing the inverse transformation
inverse<- function(x) t(x[dim(x)[1]:1, ]) 

windows(); levelplot(m, main="levelplot(m)")
windows(); levelplot(inverse(m), main="levelplot(inverse(m))")

Message: 7
Date: Mon, 11 Dec 2006 12:28:17 +0000 (GMT)
From: Jenny Barnes <jmb at mssl.ucl.ac.uk>
Subject: [R] upside down image/data
To: r-help at stat.math.ethz.ch
Message-ID: <200612111228.kBBCSHrj013960 at msslhb.mssl.ucl.ac.uk>
Content-Type: TEXT/plain; charset=us-ascii

Dear R-community,

I am looking for some simple advice - I have a matrix (therefore 2 

of global temperature. 

Having read R-help I think that when I ask R to image() or levelplot() 

will it actually appear upside down - I think I therefore need to use 

levelplot(temperature.matrix[,ncol(output.temp):1], ........)

to get it looking like it was on the globe due to the matrix rows 

number down the matrix in its dimensions on longitude and latitude but 

y-axis coordinates increase up the axis.

Can anyone simply tell me whether this is correct as I find it very 

which way up my data should be and I cannot tell which is correct 

looking at it!

Many thanks for your time in reading this problem,

Jenny Barnes