On Mon, 2005-02-28 at 14:05 -0400, Peyuco Porras Porras .
wrote:> Dear R-users
>
> A basic question that I wasn't able to solve: Is it possible to
get
> the results of the function 'quantile' expressed as
data.frame? What
> I'm doing is to apply the following code to get the quantiles in
a
> particular dataset:
>
> tmp<-tapply(data$DEN,list(Age=data$AGE,Sex=data$SEX),quantile)
>
> and then I save this output to HTML using the library R2HTML. However
> in order to format the tables in HTML I have to use the command
> HTML.data.frame(...) which allows me to define, for example, the
> number of digits in the html table.
>
> But the object 'tmp' is not a dataframe and I can't coarce
it to this
> format. Is it possible to get the results of this function as a
> dataframe? I know that I'm probably missing some important
concepts
> here but Im not very good in programming.
>
> Any hint will be appreciated
Here is one approach, using an expansion of one of the examples in
?tapply:
# Get quantiles of 'breaks' for each combination of 'wool' and
'tension'> my.tmp <- tapply(warpbreaks$breaks,
list(warpbreaks$wool, warpbreaks$tension), quantile)
# Note that my.tmp is a 2 x 6 matrix of list elements
# with each list element being the results of quantile
# on each combination of 'wool' and 'tension'
> my.tmp
L M H
A Numeric,5 Numeric,5 Numeric,5
B Numeric,5 Numeric,5 Numeric,5
For example:
> my.tmp[1, 1]
[[1]]
0% 25% 50% 75% 100%
25 26 51 54 70
Now get this into a manageable structure by taking each list element in
my.tmp and converting it into a row in a new matrix, use:
> my.mat <- do.call("rbind", my.tmp)
> my.mat
0% 25% 50% 75% 100%
[1,] 25 26 51 54 70
[2,] 14 20 29 31 44
[3,] 12 18 21 30 36
[4,] 16 21 28 39 42
[5,] 10 18 24 28 43
[6,] 13 15 17 21 28
>From there, you can set the rownames for the matrix, as you require,
based upon the combinations of the vectors in your data. For example,
using expand.grid():
> my.names <- expand.grid(dimnames(my.tmp))
> my.names
Var1 Var2
1 A L
2 B L
3 A M
4 B M
5 A H
6 B H
> rownames(my.mat) <- paste(my.names$Var1, my.names$Var2, sep =
":")
> my.mat
0% 25% 50% 75% 100%
A:L 25 26 51 54 70
B:L 14 20 29 31 44
A:M 12 18 21 30 36
B:M 16 21 28 39 42
A:H 10 18 24 28 43
B:H 13 15 17 21 28
There might be an easier way, but that's my quick thought.
HTH,
Marc Schwartz