as.folder.folderh function

Hierarchic folder to folder

Creates an object of class folder, that is a list of data frames with the same column names, from a folderh.

## S3 method for class 'folderh'
as.folder(x, elt = names(x)[2], key = attr(x, "keys")[1], ...)

Arguments

• x: object of class folderh containing N (N>1) data frames: x[[1]],..., x[[N]], related by (N-1) keys: keys[1],..., keys[N-1].
• elt: string. The name of one element of x, that is data frame, say the j-th, whose rows are distributed among the data frames of the returned folder. See details.
• key: string. The name of an element of attr(x, "keys"), that is the key, say the k-th with k<j, which is the factor whose levels are the names of the data frames of the returned folder. See details.
• ...: further arguments passed to or from other methods.

Returns

as.folder.folderh returns an object of class folder, a list of data frames with the same columns. These data frames contain the values of x[[elt]] (or x[[j]]) and the corresponding values of the data frames x[[j-1]], ... x[[k]], these correspondances being defined by the keys of the hierarchic folder. The names of these data frames are given by the levels of the key attr(x, "keys")[k]).

The rows of the data frame x[[elt]] (or x[[j]]) are distributed among the data frames of the returned folder accordingly to the levels of the key attr(x, "keys")[k]. So the row names of the l-th data frame of the returned folder consist in the rows of x[[j]] corresponding to the l-th level of the key attr(x, "keys")[k].

The column names of the data frames of the returned folder are the union of the column names of the data frames x[[k]],..., x[[j]] and are organized in two parts.

1. The first part consists in the columns of x[[k]] except the column corresponding to the key attr(x, "keys")[k].
2. For each i=k+1,...,j the column names of the data frame x[[i]] are reorganized so that the key attr(x, "keys")[i] is its first column. The columns of the reorganized data frames x[[k+1]],..., x[[j]] are concatenated. The result forms the second part.

Notice that if:

• the folderh has two data frames df1 and df2, where the factor corresponding to the key has $T$ levels, and one column of df2, say df2[, "Fa"], is a factor with levels "a1", ..., "ap"
• and the folder returned by as.folder includes $T$ data frames dat1, ..., datT,

then each of dat1, ..., datT has a column named "Fa" which is a factor with the same levels "a1", ..., "ap" as df2[, "Fa"].

Author(s)

Rachid Boumaza, Pierre Santagostini, Smail Yousfi, Gilles Hunault, Sabine Demotes-Mainard

See Also

folder, folderh. as.folder.folderh to build an object of class folder from an object of class folderh. as.data.frame.folder to build a data frame from an object of class folder. as.data.frame.folderh to build a data frame from an object of class folderh.

Examples

# First example: flowers               
data(roseflowers)
flg <- roseflowers$variety
flx <- roseflowers$flower

flfh <- folderh(flg, "rose", flx)
print(flfh)

flf <- as.folder(flfh)
print(flf)

# Second example: castles               
data(castles.dated)
cag <- castles.dated$periods
cax <- castles.dated$stones

cafh <- folderh(cag, "castle", cax)
print(cafh)

caf <- as.folder(cafh)
print(caf)

# Third example: leaves (example of a folderh of more than two data frames)
data(roseleaves)
lvr <- roseleaves$rose
lvs <- roseleaves$stem
lvl <- roseleaves$leaf
lvll <- roseleaves$leaflet

lfh <- folderh(lvr, "rose", lvs, "stem", lvl, "leaf", lvll)

lf1 <- as.folder(lfh, elt = "lvs", key = "rose")
print(lf1)

lf2 <- as.folder(lfh, elt = "lvl", key = "rose")
print(lf2)

lf3 <- as.folder(lfh, elt = "lvll", key = "rose")
print(lf3)

lf4 <- as.folder(lfh, elt = "lvll", key = "stem")
print(lf4)