aqp (version 2.1.0)

split,SoilProfileCollection-method: Split a SoilProfileCollection object into a list of SoilProfileCollection objects.

Description

This function splits a SoilProfileCollection into a list of SoilProfileCollection objects using a site-level attribute to define groups or profile ID (idname(x)).

Usage

# S4 method for SoilProfileCollection
split(x, f, drop = TRUE, ...)

Value

A list of SoilProfileCollection or NULL for empty result.

Arguments

x

SoilProfileCollection object

f

character vector naming a single site-level attribute that defines groups, a ‘factor’ in the sense that as.factor(f) defines the grouping, or a list of such factors in which case their interaction is used for the grouping.

drop

logical indicating if levels that do not occur should be dropped (if f is a factor or a list). When drop=FALSE and f contains missing values an additional group "missing" is returned.

...

additional arguments are ignored

Author

D.E. Beaudette and A.G. Brown

Details

As of aqp 1.25, omission of f argument is no longer possible, as the base R generic is overloaded by this SoilProfileCollection method. This used to result in an "identity" split, according to idname(x), e.g. a list as long as length(x), with a single-profile SoilProfileCollection per list element. Replicate this behavior using f = idname(x) or f = profile_id(x).

Examples

data(sp2)
depths(sp2) <- id ~ top + bottom

# add a more interesting site-level attribute
site(sp2) <- ~ surface

# using identity site-level attribute (profile ID)
p1 <- split(sp2, f = idname(sp2))
names(p1)
length(p1)

# using vector equal in length to number of profiles (profile ID, again)
p2 <- split(sp2, f = profile_id(sp2))
names(p2)
length(p2)

# which are both equivalent to setting `f` to NULL
p3 <- split(sp2, f = NULL)
names(p3)
length(p3)

# split on surface (age) site-level var
p4 <- split(sp2, f = "surface")
names(p4)
length(p4) # 5 unique "surfaces", 5 SPCs in result list