Query data from Kellogg Soil Survey Laboratory Data Mart via Soil Data Access or local SQLite snapshot
Source:R/fetchLDM.R
fetchLDM.Rd
LDM model diagram: https://jneme910.github.io/Lab_Data_Mart_Documentation/Documents/SDA_KSSL_Data_model.html
Usage
fetchLDM(
x = NULL,
what = "pedlabsampnum",
bycol = "pedon_key",
tables = c("lab_physical_properties", "lab_chemical_properties",
"lab_calculations_including_estimates_and_default_values", "lab_rosetta_Key"),
WHERE = NULL,
chunk.size = 1000,
ntries = 3,
layer_type = c("horizon", "layer", "reporting layer"),
area_type = c("ssa", "country", "state", "county", "mlra", "nforest", "npark"),
prep_code = c("S", ""),
analyzed_size_frac = c("<2 mm", ""),
dsn = NULL
)
Arguments
- x
A vector of values to find in column specified by
what
, defaultNULL
uses no constraints onwhat
- what
A single column name from tables:
lab_combine_nasis_ncss
,lab_webmap
,lab_site
,lab_pedon
orlab_area
- bycol
A single column name from
lab_layer
used for processing chunks; default:"pedon_key"
- tables
A vector of table names; Default is
"lab_physical_properties"
,"lab_chemical_properties"
,"lab_calculations_including_estimates_and_default_values"
, and"lab_rosetta_Key"
. May also include one or more of:"lab_mir"
,"lab_mineralogy_glass_count"
,"lab_major_and_trace_elements_and_oxides"
,"lab_xray_and_thermal"
but it will be necessary to select appropriateprep_code
andanalyzed_size_frac
for your analysis (see Details).- WHERE
character. A custom SQL WHERE clause, which overrides
x
,what
, andbycol
, such asCASE WHEN corr_name IS NOT NULL THEN LOWER(corr_name) ELSE LOWER(samp_name) END = 'musick'
- chunk.size
Number of pedons per chunk (for queries that may exceed
maxJsonLength
)- ntries
Number of tries (times to halve
chunk.size
) before returningNULL
; default3
- layer_type
Default:
"horizon"
,"layer"
, and"reporting layer"
- area_type
Default:
"ssa"
(Soil Survey Area). Other options include (choose one):"country"
,"state"
,"county"
,"mlra"
(Major Land Resource Area),"nforest"
(National Forest),"npark"
(National Park)- prep_code
Default:
"S"
and""
. May also include one or more of:"F"
,"HM"
,"HM_SK"
"GP"
,"M"
,"N"
, or"S"
- analyzed_size_frac
Default:
"<2 mm"
and""
. May also include one or more of:"<0.002 mm"
,"0.02-0.05 mm"
,"0.05-0.1 mm"
,"0.1-0.25 mm"
,"0.25-0.5 mm"
,"0.5-1 mm"
,"1-2 mm"
,"0.02-2 mm"
,"0.05-2 mm"
- dsn
Data source name; either a path to a SQLite database, an open DBIConnection or (default)
NULL
(to usesoilDB::SDA_query
)
Value
a SoilProfileCollection
for a successful query, a try-error
if no site/pedon locations can be found or NULL
for an empty lab_layer
(within sites/pedons) result
Details
If the chunk.size
parameter is set too large and the Soil Data Access request fails, the algorithm will re-try the query with a smaller (halved) chunk.size
argument. This will be attempted up to 3 times before returning NULL
Currently the lab_area
tables are joined only for the "Soil Survey Area" related records.
When requesting data from "lab_major_and_trace_elements_and_oxides"
, "lab_mineralogy_glass_count"
, or "lab_xray_and_thermal"
multiple preparation codes (prep_code
) or size fractions (analyzed_size_frac
) are possible. The default behavior of fetchLDM()
is to attempt to return a topologically valid (minimal overlaps) SoilProfileCollection. This is achieved by setting prep_code="S"
("sieved") and analyzed_size_frac="<2 mm"
. You may specify alternate or additional preparation codes or fractions as needed, but note that this may cause "duplication" of some layers where measurements were made with different preparation or on fractionated samples
Examples
if (FALSE) {
# fetch by ssa_key
res <- fetchLDM(8297, what = "ssa_key")
# physical properties correlated as taxonomic subgroup "Typic Argialbolls"
res <- fetchLDM(x = "Typic Argialbolls",
what = "corr_taxsubgrp",
tables = "lab_physical_properties")
# fetch by area_code (SSA only)
res <- fetchLDM("CA630", what = "area_code")
}