ef_fun: Experimental: Returns a function of Emission Factor by age of...

In vein: Vehicular Emissions Inventories

Experimental: Returns a function of Emission Factor by age of use

Description

ef_fun returns amount of vehicles at each age

Usage

ef_fun(
  ef,
  type = "logistic",
  x = 1:length(ef),
  x0 = mean(ef),
  k = 1/4,
  L = max(ef)
)

Arguments

ef	Numeric; numeric vector of emission factors.
type	Character; "logistic" by default so far.
x	Numeric; vector for ages of use.
x0	Numeric; the x-value of the sigmoid's midpoint,
k	Numeric; the steepness of the curve.
L	Integer; the curve's maximum value.

Value

dataframe of age distrubution of vehicles at each street.

References

https://en.wikipedia.org/wiki/Logistic_function

Examples

## Not run: 
data(fe2015)
CO <- ef_cetesb(p = "CO", veh = "PC_G")
ef_logit <- ef_fun(ef = CO, x0 = 27, k = 0.4, L = 33)
df <- data.frame(CO, ef_logit)
colplot(df)

## End(Not run)

vein documentation built on April 30, 2023, 1:10 a.m.