R/SoilProfileCollection-operators.R
doublebracket.RdGet the data from a column accessed by name. Column names other than profile ID are not shared between site and horizons.
Bonus: [[ gives access to all site and horizon level variables in tab complete for RStudio using the magrittr pipe operator!
# S4 method for class 'SoilProfileCollection'
x[[i, j]]
data(sp2)
depths(sp2) <- id ~ top + bottom
site(sp2) <- ~ surface
# get with [[
sp2[['surface']]
#> [1] holocene lower modesto lower modesto upper modesto
#> [5] upper modesto lower riverbank lower riverbank lower riverbank
#> [9] holocene lower riverbank lower laguna lower laguna
#> [13] holocene holocene upper modesto upper modesto
#> [17] upper modesto upper modesto
#> 6 Levels: holocene lower modesto upper modesto ... lower laguna
# get using "unknown" expression:
# "2nd + 3rd horizon column names"
for(i in horizonNames(sp2)[2:3])
print(sp2[[i]])
#> [1] 0 12 16 25 49 85 95 122 140 0 22 40 86 132 150 205 0 18
#> [19] 45 94 125 145 179 0 24 33 50 62 86 102 123 157 208 245 266 0
#> [37] 28 39 59 76 111 126 150 200 260 0 18 24 76 100 160 201 208 0
#> [55] 19 30 90 113 170 190 240 0 7 24 63 91 126 176 218 246 268 300
#> [73] 320 0 4 32 61 92 103 0 11 30 60 114 191 223 260 0 11 33
#> [91] 46 71 93 119 148 197 274 315 473 0 23 43 59 89 120 154 207 270
#> [109] 342 455 505 0 4 16 31 54 0 17 32 49 86 113 0 13 23 54
#> [127] 88 102 141 0 10 22 43 91 118 157 0 8 30 54 88 118 180 230
#> [145] 290 340 0 7 34 57 90 126 191 240
#> [1] 12 16 25 49 85 95 122 140 170 22 40 86 132 150 205
#> [16] 225 18 45 94 125 145 179 220 24 33 50 62 86 102 123
#> [31] 157 208 245 266 301 28 39 59 76 111 126 150 200 260 320
#> [46] 18 24 76 100 160 201 208 295 19 30 90 113 170 190 240
#> [61] 300 7 24 63 91 126 176 218 246 268 300 320 410 4 32
#> [76] 61 92 103 130 11 30 60 114 191 223 260 283 11 33 46
#> [91] 71 93 119 148 197 274 315 473 1300 23 43 59 89 120 154
#> [106] 207 270 342 455 505 1300 4 16 31 54 78 17 32 49 86
#> [121] 113 147 13 23 54 88 102 141 180 10 22 43 91 118 157
#> [136] 184 8 30 54 88 118 180 230 290 340 370 7 34 57 90
#> [151] 126 191 240 390
data(sp5)
# some column names to work with
rgb.columns <- c("R25","G25","B25")
res <- lapply(rgb.columns, function(x) {
# [[ allows you to access column names in a loop
round(sp5[[x]] * 255)
})
# rename scaled results
names(res) <- paste0(rgb.columns,"_scl")
# add horizon ID to results
result <- data.frame(hzID = hzID(sp5), do.call('cbind', res))
head(result)
#> hzID R25_scl G25_scl B25_scl
#> 1 1 105 97 87
#> 2 2 79 71 64
#> 3 3 79 71 64
#> 4 4 79 71 64
#> 5 5 140 117 92
#> 6 6 110 94 76
# join result back into horizons
horizons(sp5) <- result