These functions consist of several conversions between sand, silt and clay to texture class and visa versa, textural modifiers to rock fragments, and grain size composition to the family particle size class.
texcl_to_ssc(texcl = NULL, clay = NULL, sample = FALSE)
ssc_to_texcl(
sand = NULL,
clay = NULL,
simplify = FALSE,
as.is = FALSE,
droplevels = TRUE
)
texmod_to_fragvoltot(texmod = NULL, lieutex = NULL)
texture_to_taxpartsize(
texcl = NULL,
clay = NULL,
sand = NULL,
sandvf = NULL,
fragvoltot = NULL
)
texture_to_texmod(texture, duplicates = "combine")
fragvol_to_texmod(
object = NULL,
gravel = NULL,
cobbles = NULL,
stones = NULL,
boulders = NULL,
channers = NULL,
flagstones = NULL,
paragravel = NULL,
paracobbles = NULL,
parastones = NULL,
paraboulders = NULL,
parachanners = NULL,
paraflagstones = NULL,
as.is = TRUE,
droplevels = TRUE
)vector of texture classes than conform to the USDA code conventions (e.g. c|C, sil|SIL, sl|SL, cos|COS)
vector of clay percentages
logical: should ssc be random sampled from the lookup table? (default: FALSE)
vector of sand percentages
Passed to SoilTextureLevels() to set the number of possible texture classes. If TRUE, the ordered factor has a maximum of 12 levels, if FALSE (default) the ordered factor has a maximum of 21 levels (including e.g. very fine/fine/coarse variants)
logical: should character vectors be converted to factors? (default: TRUE)
logical: indicating whether to drop unused levels in factors. This is useful when the results have a large number of unused classes, which can waste space in tables and figures.
vector of textural modifiers that conform to the USDA code conventions (e.g. gr|GR, grv|GRV)
vector of in lieu of texture terms that conform to the USDA code conventions (e.g. gr|GR, pg|PG), only used when fragments or artifacts are > 90 percent by volume (default: NULL))
vector of very fine sand percentages
vector of total rock fragment percentages
vector of combinations of texcl, texmod, and lieutex (e.g. CL, GR-CL, CBV-S, GR)
character: specifying how multiple values should be handled, options are "combined" (e.g. 'GR & GRV) or "max"(e.g. 'GRV')
data.frame: containing the following column names: gravel, cobbles, stones, boulders, channers, flagstones, paragravel, paracobbles, parastones, paraboulders, parachanners, paraflagstones
numeric: gravel volume %
numeric: cobble volume %
numeric: stone volume %
numeric: boulder volume %
numeric: channer volume %
numeric: flagstone volume %
numeric: para gravel volume %
numeric: para cobble volume %
numeric: para stone volume %
numeric: para boulder volume %
numeric: para channer volume %
numeric: para flagstone volume %
texcl_to_ssc: A data.frame containing columns "sand","silt", "clay"
ssc_to_texcl: A character vector containing texture class
texmod_to_fragvoltot: A data.frame containing columns "fragvoltot_l",
"fragvoltot_r", "fragvoltot_h", "fragvoltot_l_nopf", "fragvoltot_r_nopf", "fragvoltot_h_nopf"
texture_to_taxpartsize: a character vector containing "taxpartsize" classes
texture_to_texmod: a character vector containing "texmod" classes
texmod_to_fragvol: a data.frame containing "texmod" and "lieutex" classes
These functions are intended to estimate missing values or allocate particle
size fractions to classes. The ssc_to_texcl() function uses the same
logic as the particle size estimator calculation in NASIS to classify sand
and clay into texture class. The results are stored in soiltexture
and used by texcl_to_ssc() as a lookup table to convert texture class
to sand, silt and clay. The function texcl_to_ssc() replicates the
functionality described by Levi (2017). The texmod_to_fragvol()
function similarly uses the logical from the
Exhibit618-11_texture_modifier.xls spreadsheet to determine the textural
modifier from the various combinations of rock and pararock fragments
(e.g. GR and PGR).
When sample = TRUE, the results can be used to estimate within-class,
marginal distributions of sand, silt, and clay fractions. It is recommended
that at least 10 samples be drawn for reasonable estimates.
The function texmod_to_fragvoltot returns a data.frame with multiple
fragvoltot columns differentiated by tailing abbreviations (e.g. _r) which
refer to the following:
l = low
r = representative
h = high
nopf = no pararock fragments (i.e. total fragments - pararock fragments)
The function texture_to_texmod() parses texture (e.g. GR-CL) to extract the texmod values from it in the scenario where it is missing from
texmod column. If multiple texmod values are present (for example in the
case of stratified textures) and duplicates = "combine" they will be combined in the output (e.g. GR & CBV). Otherwise if duplicates = "max"
the texmod with the highest rock fragment (e.g. CBV) will be returned.
Unlike the other functions, texture_to_taxpartsize() is intended to
be computed on weighted averages within the family particle size control
section. Also recall from the criteria that carbonate clay should be
subtracted from clay content and added to silt content. Similarly, if the
percent of very fine sand is known it should be subtracted from the sand,
and added to the silt content. Unlike the other functions,
texture_to_taxpartsize() is intended to be computed on weighted
averages within the family particle size control section. Also recall from
the criteria that carbonate clay should be subtracted from clay content and
added to silt content. Similarly, if the percent of very fine sand is known
it should be subtracted from the sand, and added to the silt content.
Matthew R. Levi, Modified Centroid for Estimating Sand, Silt, and Clay from Soil Texture Class, Soil Science Society of America Journal, 2017, 81(3):578-588, ISSN 1435-0661, doi:10.2136/sssaj2016.09.0301 .
# \donttest{
# example of ssc_to_texcl()
tex <- expand.grid(sand = 0:100, clay = 0:100)
tex <- subset(tex, (sand + clay) < 101)
tex$texcl <- ssc_to_texcl(sand = tex$sand, clay = tex$clay)
head(tex)
#> sand clay texcl
#> 1 0 0 si
#> 2 1 0 si
#> 3 2 0 si
#> 4 3 0 si
#> 5 4 0 si
#> 6 5 0 si
# example of texcl_to_ssc(texcl)
texcl <- c("cos", "s", "fs", "vfs", "lcos", "ls",
"lfs", "lvfs", "cosl", "sl", "fsl", "vfsl", "l",
"sil", "si", "scl", "cl", "sicl", "sc", "sic", "c"
)
test <- texcl_to_ssc(texcl)
head(test <- cbind(texcl, test), 10)
#> texcl sand silt clay
#> 1 cos 92 5 3
#> 2 s 92 5 3
#> 3 fs 92 5 3
#> 4 vfs 92 5 3
#> 5 lcos 82 12 6
#> 6 ls 82 12 6
#> 7 lfs 82 12 6
#> 8 lvfs 82 12 6
#> 9 cosl 65 25 10
#> 10 sl 65 25 10
# example of texcl_to_ssc(texcl, clay)
data(soiltexture)
st <- soiltexture$values
idx <- sample(1:length(st$texcl), 10)
st <- st[idx, ]
ssc <- texcl_to_ssc(texcl = st$texcl)
head(cbind(texcl = st$texcl, clay = ssc$clay))
#> texcl clay
#> [1,] "sil" "13"
#> [2,] "c" "55"
#> [3,] "l" "18"
#> [4,] "sil" "13"
#> [5,] "sicl" "33"
#> [6,] "scl" "27"
# example of texmod_to_fragvoltol
frags <- c("gr", "grv", "grx", "pgr", "pgrv", "pgrx")
head(texmod_to_fragvoltot(frags))
#> fragvoltot_l fragvoltot_r fragvoltot_h fragvoltot_h_nopf fragvoltot_r_nopf
#> 1 15 25 34 34 25
#> 2 35 48 59 59 48
#> 3 60 75 89 89 75
#> 4 15 25 34 0 0
#> 5 35 48 59 0 0
#> 6 60 75 89 0 0
#> fragvoltot_l_nopf
#> 1 15
#> 2 35
#> 3 60
#> 4 0
#> 5 0
#> 6 0
# example of texture_to_taxpartsize()
tex <- data.frame(texcl = c("c", "cl", "l", "ls", "s"),
clay = c(55, 33, 18, 6, 3),
sand = c(20, 33, 42, 82, 93),
fragvoltot = c(35, 15, 34, 60, 91))
tex$fpsc <- texture_to_taxpartsize(texcl = tex$texcl,
clay = tex$clay,
sand = tex$sand,
fragvoltot = tex$fragvoltot)
head(tex)
#> texcl clay sand fragvoltot fpsc
#> 1 c 55 20 35 clayey-skeletal
#> 2 cl 33 33 15 fine-loamy
#> 3 l 18 42 34 fine-loamy
#> 4 ls 6 82 60 sandy-skeletal
#> 5 s 3 93 91 fragmental
# example of texture_to_taxpartsize() with carbonate clay and very fine sand
carbclay <- rnorm(5, 2, 3)
vfs <- rnorm(5, 10, 3)
st$fpsc <- texture_to_taxpartsize(texcl = tex$texcl,
clay = tex$clay - carbclay,
sand = tex$sand - vfs,
fragvoltot = tex$fragvoltot)
#> Warning: some records are > 100% or < 0%, or the calcuated silt fraction is > 100% or < 0%
#> Warning: some of the texcl records don't match the calculated texcl via ssc_to_texcl()
head(tex)
#> texcl clay sand fragvoltot fpsc
#> 1 c 55 20 35 clayey-skeletal
#> 2 cl 33 33 15 fine-loamy
#> 3 l 18 42 34 fine-loamy
#> 4 ls 6 82 60 sandy-skeletal
#> 5 s 3 93 91 fragmental
# example of sample = TRUE
texcl <- rep(c("cl", "sil", "sl"), 10)
ssc1 <- cbind(texcl, texcl_to_ssc(texcl = texcl, sample = FALSE))
ssc2 <- cbind(texcl, texcl_to_ssc(texcl = texcl, sample = TRUE))
ssc1$sample <- FALSE
ssc2$sample <- TRUE
ssc <- rbind(ssc1, ssc2)
aggregate(clay ~ sample + texcl, data = ssc, summary)
#> sample texcl clay.Min. clay.1st Qu. clay.Median clay.Mean clay.3rd Qu.
#> 1 FALSE cl 33.00 33.00 33.00 33.00 33.00
#> 2 TRUE cl 27.00 30.25 31.50 31.80 32.75
#> 3 FALSE sil 13.00 13.00 13.00 13.00 13.00
#> 4 TRUE sil 0.00 3.50 10.50 9.80 14.50
#> 5 FALSE sl 10.00 10.00 10.00 10.00 10.00
#> 6 TRUE sl 1.00 3.50 8.50 7.90 10.75
#> clay.Max.
#> 1 33.00
#> 2 38.00
#> 3 13.00
#> 4 23.00
#> 5 10.00
#> 6 16.00
# }
# \donttest{
# example of texture_to_texmod()
tex <- c("SL", "GR-SL", "CBV-L", "SR- GR-FS GRX-COS")
texture_to_texmod(tex)
#> [1] NA "gr" "cbv" "gr & grx"
texture_to_texmod(tex, duplicates = "max")
#> [1] NA "gr" "cbv" "grx"
# }
# \donttest{
# example of fragvol_to_texmod()
df <- expand.grid(
gravel = seq(0, 100, 5),
cobbles = seq(0, 100, 5),
stones = seq(0, 100, 5),
boulders = seq(0, 100, 5)
)
df <- df[rowSums(df) < 100, ]
# data.frame input
test <- fragvol_to_texmod(df)
table(test$texmod)
#>
#> by byv byx cb cbv cbx gr grv grx st stv stx
#> 81 510 2135 37 192 710 20 82 273 57 371 1502
table(test$lieutex)
#>
#> by cb gr st
#> 1634 37 2 1197
# vector inputs
fragvol_to_texmod(gravel = 10, cobbles = 10)
#> texmod lieutex
#> 1 cb <NA>
# }