aqp (version 1.8-6)

unique-methods: Get Indices to Unique Soil Profiles Within a Collection

Description

This function returns a set of indices to a subset of profiles within a SoilProfileCollection object that are uniquely defined by a named set of horizon and site level attributes.

Usage

uniqueSPC(x, vars)

Arguments

x

a SoilProfileCollection

vars

a character vector naming those horizon and site level attributes that will be used to test for duplication

Value

• A vector of integer indices that can be used to subset unique profiles from the original SoilProfileCollection object.

Details

Duplicates are identified via MD5 hash of select horizon and site level attributes.

Examples

## use the digest library to detect duplicate data
data(sp1)

# make a copy, make new IDs, and stack
s.1 <- sp1 
s.2 <- sp1
s.2$id <- paste(s.2$id, '-copy', sep='')
s <- rbind(s.1, s.2)
depths(s) <- id ~ top + bottom

# digests are computed from horizon-level data only
# horizon boundaries and 'prop'
# result is an index of unqique profiles

u <- unique(s, vars=c('top', 'bottom', 'prop'))

# compare with and without dupes:
# note subsetting of SoilProfileCollection
cbind(dupes=length(s), no.dupes=length(s[u, ]))