weibull4.build: weibull 4-parameters distribution building function

In weibull4: Fits Data into 4-Parameters Weibull Distribution

Description

Builds data for a 4-parameters Weibull distribution of a given x data

Usage

weibull4.build(x=seq(0,1,length.out=10), shape=2.5, scale=1, loc=0, area=20,
shape2=5, scale2=2, loc2=6, area2=1, modes=1)

Arguments

x	Vector: data range for calculation of the Weibull distribution. If it is NULL, it will be set to seq(0,1,0.1)
shape	Weibull's shape parameter
scale	Weibull's scale parameter
loc	Weibull's location parameter
area	Weibull's area parameter: area under the PDF curve
shape2	second mode Weibull's shape parameter. It works only if modes=2.
scale2	second mode Weibull's scale parameter. It works only if modes=2.
loc2	second mode Weibull's location parameter. It works only if modes=2.
area2	second mode Weibull's area parameter. It works only if modes=2.
modes	Sets whether data may be fit with unimodal or bimodal Weibull distribution. This option was implemented to fit data feom the second wave of infections and deaths for COVID-19. Use modes=1 for unimodal distribution (single peak) and modes=2 for bimodal distribution (two peaks).

Details

This package was specially built to fit COVID-19 data on the number of daily new cases and deaths in countries. So x must be integer. Alternatively, Date format is allowed

Value

Vector: f(x) Weibull distribution's ordinate

Warning

This package is a secondary product of the reffered science paper. Please, note that there is no warrants or professional support on its use

Note

Comments, suggestions and doubts must be sent to [e-mail]

Author(s)

Vitor Hugo Moreau, Ph.D.

References

MOREAU, V. H. (2021) Using the Weibull distribution to model COVID-19 epidemic data. Modeling Assited Statistics Applications, 2021, in press.

Examples

## Build a 4-parameters Weibull distribution with given parameters
weibull4.build(seq(1,100,1), shape=2.5, scale=30, loc=10, area=1000, modes=1)
## Build and plot 4-parameters Weibull distribution with given parameters
plot(seq(1,100,1), weibull4.build(seq(1,100,1), 2, 30, 10, 1), type="l")
## Build and plot 4-parameters Weibull distribution with a time series in the abscissa
Date <- seq(Sys.Date(), as.Date("2022-12-31"),1)
plot(Date, weibull4.build(Date, 1.6, 100, 100, 100), type="l")
## Build and plot a bimodal, 4-parameters Weibull distribution with given parameters
weibull4.build(seq(1,100,1), shape=2.5, scale=30, loc=10, area=1000,
shape2=2.5, scale2=60, loc2=40, area2=1000, modes=2)

weibull4 documentation built on Jan. 26, 2021, 1:06 a.m.