Summarize soil color data, weighted by occurrence and horizon thickness.

aggregateColor(x, groups = "genhz", col = "soil_color")

Arguments

x

a SoilProfileCollection object

groups

the name of a horizon or site attribute used to group horizons, see examples

col

the name of a horizon-level attribute with soil color specified in hexadecimal (i.e. "#rrggbb")

Value

A list with the following components:

Details

Weights are computed by: w_i = sqrt(sum(thickness_i)) * n_i where w_i is the weight associated with color i, thickness_i is the total thickness of all horizons associated with the color i, and n_i is the number of horizons associated with color i. Weights are computed within groups specified by groups.

See also

generalize.hz

Examples

# load some example data
data(sp1, package='aqp')

# upgrade to SoilProfileCollection and convert Munsell colors
sp1$soil_color <- with(sp1, munsell2rgb(hue, value, chroma))
depths(sp1) <- id ~ top + bottom
site(sp1) <- ~ group

# generalize horizon names
n <- c('O', 'A', 'B', 'C')
p <- c('O', 'A', 'B', 'C')
sp1$genhz <- generalize.hz(sp1$name, n, p)

# aggregate colors over horizon-level attribute: 'genhz'
a <- aggregateColor(sp1, 'genhz')

# aggregate colors over site-level attribute: 'group'
a <- aggregateColor(sp1, 'group')

# aggregate colors over depth-slices
s <- slice(sp1, c(5, 10, 15, 25, 50, 100, 150) ~ soil_color)
s$slice <- paste0(s$top, ' cm')
a <- aggregateColor(s, 'slice')

## Not run: ------------------------------------
# # optionally plot with helper function
# if(require(sharpshootR))
#   aggregateColorPlot(a)
## ---------------------------------------------

# a more interesting example
## Not run: ------------------------------------
# data(loafercreek, package = 'soilDB')
# 
# # generalize horizon names using REGEX rules
# n <- c('Oi', 'A', 'BA','Bt1','Bt2','Bt3','Cr','R')
# p <- c('O', '^A$|Ad|Ap|AB','BA$|Bw', 
# 'Bt1$|^B$','^Bt$|^Bt2$','^Bt3|^Bt4|CBt$|BCt$|2Bt|2CB$|^C$','Cr','R')
# loafercreek$genhz <- generalize.hz(loafercreek$hzname, n, p)
# 
# # remove non-matching generalized horizon names
# loafercreek$genhz[loafercreek$genhz == 'not-used'] <- NA
# loafercreek$genhz <- factor(loafercreek$genhz)
# 
# a <- aggregateColor(loafercreek, 'genhz')
# 
# # plot results with helper function
# par(mar=c(1,4,4,1))
# aggregateColorPlot(a, print.n.hz = TRUE)
# 
# # inspect aggregate data
# a$aggregate.data
## ---------------------------------------------