fweibull {fitplc}

Weibull vulnerability curve

Description

The Weibull function, as re-parameterized by Ogle et al. (2009), which describes the relative conductivity as a function of the plant water potential. The relative conductivity (relK) is scaled to be 1 when water potential is zero. The slope of relK versus P at the inflection point can be calculated from the shape parameter (SX) as slope = -SX/100.

Usage

fweibull(P, SX, PX, X = 50)

Arguments

P

Water potential (positive-valued MPa)

SX

Shape parameter

PX

Water potential at X loss of conductivity.

X

If 50, PX is the P50.

References

Ogle, K., Barber, J.J., Willson, C., Thompson, B., 2009. Hierarchical statistical modeling of xylem vulnerability to cavitation. New Phytologist 182, 541-554.

Examples

curve(fweibull(x, SX=30, PX=2), from=0, to=5)