Estimate the fraction of species potentially affected at a concentration.

Usage

ssd_paf(
  analyte,
  conc,
  conc_units = NULL,
  method = c("multi", "anzecc"),
  hardness = NULL,
  hardness_units = NULL,
  hardness_cv = 0.05,
  guideline_dir = getOption("hydroSense.guideline_dir"),
  nboot = 0L,
  level = 0.95
)

Arguments

analyte: Character. Analyte name (key in .SSD_NAME_MAP). Supply "NO3-N" together with hardness for automatic class selection, or supply the explicit class name ("NO3-N_soft" etc.).
conc: Numeric or units object. Concentration to evaluate. Bare numeric requires conc_units.
conc_units: Character. Unit of conc when it is bare numeric, e.g. "ug/L" or "mg/L". Ignored when conc is a units object.
method: Character. "multi" (default) fits all 6 BCANZ distributions and model-averages; "anzecc" uses the per-analyte distribution that best matches the original ANZG derivation.
hardness: Numeric or units object, or NULL. Required for the NO3-N analyte. Hardness at the time of measurement. Bare numeric requires hardness_units.
hardness_units: Character. Unit of hardness when it is bare numeric, e.g. "mg/L". Ignored when hardness is a units object or NULL.
hardness_cv: Numeric. CV of the hardness measurement, used to weight the three NO3-N hardness-class SSDs probabilistically (a log-normal blend that smooths the soft/moderate/hard boundaries). Default 0.05 (5%). Set to 0 to recover hard class cutoffs.
guideline_dir: Character. Path to the "guideline data" folder containing ANZG XLSX files. Falls back to getOption("hydroSense.guideline_dir").
nboot: Integer. Bootstrap replicates for CI. 0 = no CI.
level: Numeric. Confidence level (default 0.95).

Value

Named list: $analyte character $conc_ug_L numeric — resolved concentration in µg/L $method character $pct numeric — % species affected, NA if no model $lower numeric — lower CI % $upper numeric — upper CI % $note character vector — caveats

Examples

# Fraction of species affected by 9.3 mg/L total ammonia-N at the pH 7.0 /
# 20 degC index condition. Uses the package's bundled SSD data; set
# options(hydroSense.guideline_dir=) to fit from the ANZG XLSX files.
ssd_paf("NH3-N", conc = 9321, conc_units = "ug/L")
#> $analyte
#> [1] "NH3-N"
#> 
#> $conc_ug_L
#> [1] 9321
#> 
#> $method
#> [1] "multi"
#> 
#> $pct
#> [1] 49.99988
#> 
#> $lower
#> [1] NA
#> 
#> $upper
#> [1] NA
#> 
#> $note
#> character(0)
#> 

# NO3-N needs hardness for automatic soft/moderate/hard SSD selection:
ssd_paf("NO3-N", conc = 50000, conc_units = "ug/L",
        hardness = 90, hardness_units = "mg/L")
#> $analyte
#> [1] "NO3-N"
#> 
#> $conc_ug_L
#> [1] 50000
#> 
#> $method
#> [1] "multi"
#> 
#> $pct
#> [1] 74.51201
#> 
#> $lower
#> [1] NA
#> 
#> $upper
#> [1] NA
#> 
#> $note
#> [1] "NO3-N hardness blend (soft/mod/hard = 0.00/1.00/0.00)"
#>