**Subject: **Re: image stops detecting wrong sized z matrix (PR#352)

*ripley@stats.ox.ac.uk*

**Date: **Wed 01 Dec 1999 - 00:16:55 EST

**Next message:**rnassar@duke.edu: "odd result of length() with factor arguments with NA (PR#354)"**Previous message:**albrecht.gebhardt@uni-klu.ac.at: "image stops detecting wrong sized z matrix (PR#352)"**Maybe in reply to:**albrecht.gebhardt@uni-klu.ac.at: "image stops detecting wrong sized z matrix (PR#352)"**Maybe reply:**ripley@stats.ox.ac.uk: "Re: image stops detecting wrong sized z matrix (PR#352)"

Message-Id: <199911301416.PAA29330@pubhealth.ku.dk>

[...]

*> This is where example(krige) from library(sgeostat) stops with R 0.90.0:
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*>
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*> krige> image(grid$x, grid$y, grid$krige$zhat, add = T)
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*> Error in length(x) == nrow(z) : comparison (1) is possible only for vector
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*> types
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*>
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*> in previous versions of R the above image() call worked, because image()
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*> did the transformation
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*>
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*> grid$krige$zhat -> matrix(grid$krige$zhat,length(grid$x),length(grid$x))
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*>
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*> iself. (BTW, contour() didn't)
*

(In fact, it just ignored dim(z) which therefore could be null.)

*> Was this change of behaviour in image() made intentionally?
*

Yes, to allow a more general specification of x and y, for S compatibility

(and general usefulness!).

I believe this is a bug in sgeostat not in R: it has long been

documented that z should be a matrix. What has happened is that we

now make use of the documented behaviour. Suppose z were of length 90,

and each of x and y were of length 10. That is now ambiguous (and BTW,

just gave the wrong plot in 0.65.1, something that has caught me

more than once).

I will add a more specific error message testing that z is a matrix.

-- Brian D. Ripley, ripley@stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._

**Next message:**rnassar@duke.edu: "odd result of length() with factor arguments with NA (PR#354)"**Previous message:**albrecht.gebhardt@uni-klu.ac.at: "image stops detecting wrong sized z matrix (PR#352)"**Maybe in reply to:**albrecht.gebhardt@uni-klu.ac.at: "image stops detecting wrong sized z matrix (PR#352)"**Maybe reply:**ripley@stats.ox.ac.uk: "Re: image stops detecting wrong sized z matrix (PR#352)"

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