problem with as.table (PR#8652)

I.J.Wilson at ncl.ac.uk writes:

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There is a problem with as.table converting from a matrix with
more than 26 rows (or columns) .

rows past 26 are set to <NA>.  This makes operations such as
turning the data back into a data.frame difficult.

example causing problems:

b <-  as.table(matrix(1:60,ncol=2))
as.integer(as.data.frame(b)[,1])

You can add dimnames to b or the original matrix for a workaround.

Probably the easiest fix is (in as.table.default) to replace

 LETTERS[seq(length = dim(x)[i])]

with 

 make.unique(LETTERS[seq(from=0, length = dim(x)[i]) %% 26 + 1], sep="")

The effect would be like

make.unique(LETTERS[(0:59)%%26+1], sep="")

[1] "A"  "B"  "C"  "D"  "E"  "F"  "G"  "H"  "I"  "J"  "K"  "L"  "M"  "N"  "O"
[16] "P"  "Q"  "R"  "S"  "T"  "U"  "V"  "W"  "X"  "Y"  "Z"  "A1" "B1" "C1" "D1"
[31] "E1" "F1" "G1" "H1" "I1" "J1" "K1" "L1" "M1" "N1" "O1" "P1" "Q1" "R1" "S1"
[46] "T1" "U1" "V1" "W1" "X1" "Y1" "Z1" "A2" "B2" "C2" "D2" "E2" "F2" "G2" "H2"

Users might prefer a different scheme, but wouldn't really deserve
it... (If they want otherwise, they can just set it themselves).

O__  ---- Peter Dalgaard             ?ster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907