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ptfkit.cosby1984

ptfkit.cosby1984

Cosby et al. (1984), United States.

Reference

Cosby, B. J., Hornberger, G. M., Clapp, R. B., & Ginn, T. R. (1984). A statistical exploration of the relationships of soil moisture characteristics to the physical properties of soils. Water Resources Research, 20(6), 682-690.

Territory

United States

Dataset

1448 soil samples from Holtan et al. (1968) and Rawls et al. (1976).

CLASS DESCRIPTION
Cosby1984UnivariatePTFResult

Results returned by the matching PTF.
FUNCTION DESCRIPTION
calc_ptf_cosby1984_univariate

Estimate Cosby et al. (1984) univariate hydraulic parameter statistics from soil texture.

Cosby1984UnivariatePTFResult

Bases: NamedTuple, Generic[T]

Results returned by the matching PTF.

ATTRIBUTE DESCRIPTION
mean_b

Mean slope of the moisture characteristic. (dimensionless)

TYPE: T

mean_log_psi_s

Mean log saturation matric potential; the underlying potential is expressed in cm H2O. (reported log value)

TYPE: T

mean_log_k_sat

Mean log saturated hydraulic conductivity; the underlying conductivity is expressed in inches per hour. (reported log value)

TYPE: T

mean_theta_s

Mean saturated water content. (% volume/volume)

TYPE: T

sd_b

Standard deviation of b. (dimensionless)

TYPE: T

sd_log_k_sat

Standard deviation of log saturated hydraulic conductivity. (reported log value)

TYPE: T

sd_theta_s

Standard deviation of saturated water content. (% volume/volume)

TYPE: T

Source code in ptfkit/cosby1984.py 
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class Cosby1984UnivariatePTFResult(NamedTuple, Generic[T]):
    """Results returned by the matching PTF.

    Attributes:
        mean_b: Mean slope of the moisture characteristic. (dimensionless)
        mean_log_psi_s: Mean log saturation matric potential; the underlying potential is expressed
            in cm H2O. (reported log value)
        mean_log_k_sat: Mean log saturated hydraulic conductivity; the underlying conductivity is
            expressed in inches per hour. (reported log value)
        mean_theta_s: Mean saturated water content. (% volume/volume)
        sd_b: Standard deviation of b. (dimensionless)
        sd_log_k_sat: Standard deviation of log saturated hydraulic conductivity. (reported log
            value)
        sd_theta_s: Standard deviation of saturated water content. (% volume/volume)

    """

    mean_b: T
    mean_log_psi_s: T
    mean_log_k_sat: T
    mean_theta_s: T
    sd_b: T
    sd_log_k_sat: T
    sd_theta_s: T

calc_ptf_cosby1984_univariate 

calc_ptf_cosby1984_univariate(*, sand: float, silt: float, clay: float) -> Cosby1984UnivariatePTFResult[floating]

calc_ptf_cosby1984_univariate(*, sand: ArrayLike, silt: ArrayLike, clay: ArrayLike, out: Cosby1984UnivariatePTFResult[NDArray[floating]] | None = None) -> Cosby1984UnivariatePTFResult[NDArray[floating]]

Estimate Cosby et al. (1984) univariate hydraulic parameter statistics from soil texture.

PARAMETER DESCRIPTION
sand

Sand content. (%)

TYPE: float | ArrayLike

silt

Silt content. (%)

TYPE: float | ArrayLike

clay

Clay content. (%)

TYPE: float | ArrayLike

out

Optional output arrays for in-place calculation.

TYPE: Cosby1984UnivariatePTFResult[NDArray[floating]] | None DEFAULT: None

RETURNS DESCRIPTION
Cosby1984UnivariatePTFResult

Results grouped by result attributes.

TYPE: Cosby1984UnivariatePTFResult[floating] | Cosby1984UnivariatePTFResult[NDArray[floating]]

Models

\(h(\theta)\): Power function moisture characteristic \(k(h)\): Saturated hydraulic conductivity parameter statistics

Notes

Prediction target: Mean and standard deviation estimates for hydraulic parameters from sand, silt, and clay percentages. No back-transform is applied to logarithmic outputs. Public API names are provisional for pilot testing.

Warning

Log-transformed output units use the pilot contract reported log value.

Source code in ptfkit/cosby1984.py 
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def calc_ptf_cosby1984_univariate(
    *,
    sand: float | ArrayLike,
    silt: float | ArrayLike,
    clay: float | ArrayLike,
    out: Cosby1984UnivariatePTFResult[NDArray[floating]] | None = None,
) -> Cosby1984UnivariatePTFResult[floating] | Cosby1984UnivariatePTFResult[NDArray[floating]]:
    r"""Estimate Cosby et al. (1984) univariate hydraulic parameter statistics from soil texture.

    Arguments:
        sand: Sand content. (%)
        silt: Silt content. (%)
        clay: Clay content. (%)
        out: Optional output arrays for in-place calculation.

    Returns:
        Cosby1984UnivariatePTFResult: Results grouped by result attributes.

    Models:
        $h(\theta)$: Power function moisture characteristic
        $k(h)$: Saturated hydraulic conductivity parameter statistics

    Notes:
        Prediction target: Mean and standard deviation estimates for hydraulic parameters from sand,
            silt, and clay percentages.
        No back-transform is applied to logarithmic outputs.
        Public API names are provisional for pilot testing.

    Warning:
        Log-transformed output units use the pilot contract `reported log value`.

    """
    values = _call(
        _calc_ptf_cosby1984_univariate,
        sand,
        silt,
        clay,
        out=out,
    )

    return Cosby1984UnivariatePTFResult(*values)