logistic {AgroReg} | R Documentation |

Logistic models with three (L.3), four (L.4) or five (L.5) continuous data parameters. This model was extracted from the drc package.

```
logistic(
trat,
resp,
npar = "L.3",
sample.curve = 1000,
ylab = "Dependent",
xlab = "Independent",
theme = theme_classic(),
legend.position = "top",
error = "SE",
r2 = "all",
ic = FALSE,
fill.ic = "gray70",
alpha.ic = 0.5,
point = "all",
width.bar = NA,
scale = "none",
textsize = 12,
pointsize = 4.5,
linesize = 0.8,
linetype = 1,
pointshape = 21,
fillshape = "gray",
colorline = "black",
round = NA,
xname.formula = "x",
yname.formula = "y",
comment = NA,
fontfamily = "sans"
)
```

`trat` |
Numeric vector with dependent variable. |

`resp` |
Numeric vector with independent variable. |

`npar` |
Number of model parameters |

`sample.curve` |
Provide the number of observations to simulate curvature (default is 1000) |

`ylab` |
Variable response name (Accepts the |

`xlab` |
treatments name (Accepts the |

`theme` |
ggplot2 theme ( |

`legend.position` |
legend position ( |

`error` |
Error bar (It can be SE - |

`r2` |
coefficient of determination of the mean or all values ( |

`ic` |
Add interval of confidence |

`fill.ic` |
Color interval of confidence |

`alpha.ic` |
confidence interval transparency level |

`point` |
defines whether you want to plot all points ("all") or only the mean ("mean") |

`width.bar` |
Bar width |

`scale` |
Sets x scale ( |

`textsize` |
Font size |

`pointsize` |
shape size |

`linesize` |
line size |

`linetype` |
line type |

`pointshape` |
format point (default is 21) |

`fillshape` |
Fill shape |

`colorline` |
Color lines |

`round` |
round equation |

`xname.formula` |
Name of x in the equation |

`yname.formula` |
Name of y in the equation |

`comment` |
Add text after equation |

`fontfamily` |
Font family |

The three-parameter logistic function with lower limit 0 is

`y = 0 + \frac{d}{1+\exp(b(x-e))}`

The four-parameter logistic function is given by the expression

`y = c + \frac{d-c}{1+\exp(b(x-e))}`

The five-parameter logistic function is given by the expression

`y = c + \frac{d-c}{1+\exp(b(x-e))^f}`

The function is symmetric about the inflection point (e).

The function returns a list containing the coefficients and their respective values of p; statistical parameters such as AIC, BIC, pseudo-R2, RMSE (root mean square error); largest and smallest estimated value and the graph using ggplot2 with the equation automatically.

Model imported from the drc package (Ritz et al., 2016)

Gabriel Danilo Shimizu

Leandro Simoes Azeredo Goncalves

Seber, G. A. F. and Wild, C. J (1989) Nonlinear Regression, New York: Wiley & Sons (p. 330).

Ritz, C.; Strebig, J.C.; Ritz, M.C. Package ‘drc’. Creative Commons: Mountain View, CA, USA, 2016.

```
library(AgroReg)
data("aristolochia")
attach(aristolochia)
logistic(trat,resp)
```

[Package *AgroReg* version 1.2.9 Index]