[R] Surprise when mapping matrix to image

Peter Dalgaard p.dalgaard at biostat.ku.dk
Fri Aug 27 08:46:57 CEST 2004

"Richard A. O'Keefe" <ok at cs.otago.ac.nz> writes:

> How about this addition to the documentation?
>     "The x axis corresponds to the rows of the matrix (first on the left
>      to last on the right).  The y axis corresponds to the columns of the
>      matrix (first at the bottom to last at the top)."
> Once you know what image() is _intended_ to do with a matrix,
> you can figure out the transposing and reversing you need for any
> other view.  It's knowing you need to that's the problem.

Good idea, but perhaps not phrased sharply enough to catch the user's
eye. How about something like this:

"Notice that image() interprets a matrix as a table of f(x_i, y_j), so
the x axis corresponds to row number and the y axis to column number
(bottom to top)."

and then use Brian's one-liner in the examples section?

   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907

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