SPC-unique-methods: Get Indices to Unique Soil Profiles Within a Collection
In aqp: Algorithms for Quantitative Pedology

Description Usage Arguments Details Value Methods Author(s) Examples

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.

1	uniqueSPC(x, vars)

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

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

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

signature(x = "SoilProfileCollection")

D.E. Beaudette

## 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, ]))