R help - Jun 2006 - zero.print in print.table after adding margins

The function addmargins() adds margins to a table, but returns a matrix.
But even after converted to a table the print.zero="." option of
print.table() does not work:
> x <- sample( 1:7, 20, replace=T )
> y <- sample( 1:7, 20, replace=T )
> tt <- table( x, y )
> tx <- as.table( addmargins( table( x, y ) ) )
> print( tt, zero.print="." )
   y
x   1 2 3 4 5 6 7
  1 1 2 2 . . 1 .
  2 1 . . 1 . . .
  3 . . . . . . 2
  4 1 . . . . 1 .
  5 1 . 1 . . 1 .
  6 . 1 . 1 . . .
  7 . . 1 . 1 1 .
> print( tx, zero.print="." )
     y
x      1  2  3  4  5  6  7 Sum
  1    1  2  2  0  0  1  0   6
  2    1  0  0  1  0  0  0   2
  3    0  0  0  0  0  0  2   2
  4    1  0  0  0  0  1  0   2
  5    1  0  1  0  0  1  0   3
  6    0  1  0  1  0  0  0   2
  7    0  0  1  0  1  1  0   3
  Sum  4  3  4  2  1  4  2  20

Is this a facility of print.table?
The attributes() of tt and tx have identical stucture. 

Best,
Bendix
----------------------
Bendix Carstensen
Senior Statistician
Steno Diabetes Center
Niels Steensens Vej 2
DK-2820 Gentofte
Denmark
tel: +45 44 43 87 38
mob: +45 30 75 87 38
fax: +45 44 43 07 06
bxc at steno.dk
www.biostat.ku.dk/~bxc

"BXC (Bendix Carstensen)" <bxc at steno.dk> writes:
> The function addmargins() adds margins to a table, but returns a matrix.
> But even after converted to a table the print.zero="." option of
> print.table() does not work:
> 
> > x <- sample( 1:7, 20, replace=T )
> > y <- sample( 1:7, 20, replace=T )
> > tt <- table( x, y )
> > tx <- as.table( addmargins( table( x, y ) ) )
> > print( tt, zero.print="." )
>    y
> x   1 2 3 4 5 6 7
>   1 1 2 2 . . 1 .
>   2 1 . . 1 . . .
>   3 . . . . . . 2
>   4 1 . . . . 1 .
>   5 1 . 1 . . 1 .
>   6 . 1 . 1 . . .
>   7 . . 1 . 1 1 .
> > print( tx, zero.print="." )
>      y
> x      1  2  3  4  5  6  7 Sum
>   1    1  2  2  0  0  1  0   6
>   2    1  0  0  1  0  0  0   2
>   3    0  0  0  0  0  0  2   2
>   4    1  0  0  0  0  1  0   2
>   5    1  0  1  0  0  1  0   3
>   6    0  1  0  1  0  0  0   2
>   7    0  0  1  0  1  1  0   3
>   Sum  4  3  4  2  1  4  2  20
> 
> Is this a facility of print.table?
> The attributes() of tt and tx have identical stucture. 
It appears to be intentional.

print.table has

    if (is.integer(x) && zero.print != "0" && any(i0
<- !ina &
        x == 0))
        xx[i0] <- sub("0", zero.print, xx[i0])

and of course,
> storage.mode(tx)
[1] "double"
> storage.mode(tt)
[1] "integer"

The reason could be that it is not entirely clear what to expect for
values that are zero up to round-off.

storage.mode(tx) <- "integer" fixes things up.

-- 
   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

>>>>> "PD" == Peter Dalgaard <p.dalgaard at
biostat.ku.dk>
>>>>>     on 29 Jun 2006 12:18:13 +0200 writes:
 PD> "BXC (Bendix Carstensen)" <bxc at steno.dk> writes:
 PD> 
 PD> > The function addmargins() adds margins to a table, but returns a
matrix.
 PD> > But even after converted to a table the print.zero="."
option of
 PD> > print.table() does not work:
 PD> > 
 PD> > > x <- sample( 1:7, 20, replace=T )
 PD> > > y <- sample( 1:7, 20, replace=T )
 PD> > > tt <- table( x, y )
 PD> > > tx <- as.table( addmargins( table( x, y ) ) )
 PD> > > print( tt, zero.print="." )
 PD> >    y
 PD> > x   1 2 3 4 5 6 7
 PD> >   1 1 2 2 . . 1 .
 PD> >   2 1 . . 1 . . .
 PD> >   3 . . . . . . 2
 PD> >   4 1 . . . . 1 .
 PD> >   5 1 . 1 . . 1 .
 PD> >   6 . 1 . 1 . . .
 PD> >   7 . . 1 . 1 1 .
 PD> > > print( tx, zero.print="." )
 PD> >      y
 PD> > x      1  2  3  4  5  6  7 Sum
 PD> >   1    1  2  2  0  0  1  0   6
 PD> >   2    1  0  0  1  0  0  0   2
 PD> >   3    0  0  0  0  0  0  2   2
 PD> >   4    1  0  0  0  0  1  0   2
 PD> >   5    1  0  1  0  0  1  0   3
 PD> >   6    0  1  0  1  0  0  0   2
 PD> >   7    0  0  1  0  1  1  0   3
 PD> >   Sum  4  3  4  2  1  4  2  20
 PD> > 
 PD> > Is this a facility of print.table?
 PD> > The attributes() of tt and tx have identical stucture. 
 PD> 
 PD> It appears to be intentional.
 PD> 
 PD> print.table has
 PD> 
 PD>     if (is.integer(x) && zero.print != "0" &&
any(i0 <- !ina &
 PD>         x == 0))
 PD>         xx[i0] <- sub("0", zero.print, xx[i0])
 PD> 
 PD> and of course,
 PD> 
 PD> > storage.mode(tx)
 PD> [1] "double"
 PD> > storage.mode(tt)
 PD> [1] "integer"
 PD> 
 PD> The reason could be that it is not entirely clear what to expect for
 PD> values that are zero up to round-off.
 PD> 
 PD> storage.mode(tx) <- "integer" fixes things up.

On the other hand, I'm pretty sure I was the one who added
'zero.print' and I don't oppose at all to change

   is.integer(x)   to   all(x == round(x))

{and then for efficiency swap the *order* of the tests inside that if(.)}

which I think would be a bit more convenient and still ok (*)
here.

Martin Maechler, ETH Zurich

(*) yes, one could then construct artificial cases where the
    if(.) test would ``conceptually'' be wrong, but I think that
    would not matter for all practical cases.