`ef_fun`

returns amount of vehicles at each age

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

ef | Numeric; numeric vector of emission factors. |
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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. |

dataframe of age distrubution of vehicles at each street.

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

if (FALSE) { data(fe2015) CO <- vein::EmissionFactors(fe2015[fe2015$Pollutant == "CO", "PC_G"]) ef_logit <- ef_fun(ef = CO, x0 = 27, k = 0.4, L = 33) plot(ef_logit, type = "b", pch = 16) lines(ef_logit, pch = 16, col = "blue") }