Start with:

> x <- c(1:7,1)
> dim(x) <- c(2,4)
> x
     [,1] [,2] [,3] [,4]
[1,]    1    3    5    7
[2,]    2    4    6    1

2 Rows of 4 Columns.  Upper-left and lower-right elements of the matrix
are the same.

All to this point makes good sense.  

> image(x)

However, this image shows 2 columns of 4 rows.  The lower-left and
upper-right elements are the same.   This does not make sense to me.
Did I miss some simple parameter to "fix" all of this naturally?  Why
would the numeric matrix of "x" and the image of "x" have such a
different geometry?

I'd love to use R for some simple image processing, but I don't want to
spend my time "fixing" all my images.

Because Image Pro Plus wasn't doing a calculation the way we wanted, I
dumped 16-bit pixel data into Excel and used Excel to create CSVs.  All
of this went much faster than figuring out the "surprise" that R didn't
display the images "correctly".  Did I miss something simple?  

I really don't want to do this:

ReadImageMatrix <- function(filename)
{
  x <- as.matrix(read.csv(filename,header=FALSE))
  x <- t(x)
  return( x[,ncol(x):1] )
}

oldpar <- par(mfrow=c(2,2))

x <-  ReadImageMatrix("1n.csv")
image(x, col=gray((0:255)/255), main="1N", axes=FALSE)

y <- ReadImageMatrix("2n.csv")
image(y, col=gray((0:255)/255), main="2N", axes=FALSE)

z <- ReadImageMatrix("3n.csv")
image(z, col=gray((0:255)/255), main="3N", axes=FALSE)

par(oldpar)
 


efg
--
Earl F. Glynn    
Scientific Programmer
Stowers Institute for Medical Research


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