Running examples in 'aqp-Ex.R' failed
The error most likely occurred in:

> ### Name: estimateSoilDepth
> ### Title: Estimate Soil Depth
> ### Aliases: estimateSoilDepth
> ### Keywords: manip
> 
> ### ** Examples
> 
> 
> 
> ## consider a situation where there were multiple candidate
> ## "contacts": 2 Cd horizons over an R
> 
> # init hypothetical profile
> d <- data.frame(
+   id = '1',
+   top = c(0, 10, 20, 30, 40, 50, 60),
+   bottom = c(10, 20, 30, 40, 50, 60, 80),
+   name = c('A', 'Bt1', 'Bt2', 'BC', 'Cd1', 'Cd2', 'R'),
+   stringsAsFactors = FALSE
+ )
> 
> # upgrade to SPC
> depths(d) <- id ~ top + bottom
> 
> # init horizon designation
> hzdesgnname(d) <- 'name'
> 
> # visual check
> par(mar = c(0, 0, 0, 1))
> plotSPC(d, hz.depths = TRUE, name.style = 'center-center', cex.names = 1, width = 0.1)
> 
> # top of the first Cd
> estimateSoilDepth(d, name = 'name')
[1] 40
> 
> # top of the first Cd
> estimateSoilDepth(d, name = 'name', selection = min)
[1] 40
> 
> # top of the R
> estimateSoilDepth(d, name = 'name', selection = max)
[1] 60
> 
> # top of the second Cd
> estimateSoilDepth(d, name = 'name', selection = max, p = 'Cd')
[1] 50
> 
> 
> ## another example
> 
> data(sp1)
> depths(sp1) <- id ~ top + bottom
> 
> # init horizon designation
> hzdesgnname(d) <- 'name'
> 
> # apply to each profile in a collection, and save as site-level attribute
> sp1$depth <- profileApply(sp1, estimateSoilDepth, name='name')
> 
> # this function can be used to "find" depth to any feature 
> # that can be defined via REGEX pattern matching on the horizon name
> # for example, locate the depth to the top "Bt" horizon
> # returning NA when there is no match
> sp1$top_Bt <- profileApply(
+   sp1, estimateSoilDepth, 
+   name='name', 
+   p='Bt', 
+   no.contact.depth=0, 
+   no.contact.assigned=NA
+ )
> 
> # reduced margins
> par(mar=c(1,1,1,2))
> # adjust default y-offset and depth scaling for following examples
> plotSPC(sp1, y.offset=10, scaling.factor=0.5)
> 
> # get plotting parameters for profile widths and depth scaling factors
> lsp <- get("last_spc_plot", envir = aqp.env)
> 
> # positions on x-axis, same for both depth and top "Bt" horizon
> x.positions <- (1:length(sp1)) - lsp$width
> 
> # annotate contact with unicode right-arrow
> # y-position is adjusted based on plot y-offset and scaling factor
> y.positions <- lsp$y.offset + (sp1$depth * lsp$scaling.factor)
> text(x.positions, y.positions, '\u2192', col='red', adj=1, cex=1.25, lwd=2)
Error in text.default(x.positions, y.positions, "→", col = "red", adj = 1,  : 
  conversion failure on '→' in 'mbcsToSbcs': for →
Calls: text -> text.default
Execution halted