[R] Plot histogram and lognormal fit on the same time

[Rui Barradas]

Hello,

A solution based on Marc's first one, maybe easier? (It doesn't rely on 
multiplying the dlnorm values by 400 since it plots the histogram with 
freq = FALSE.)


set.seed(2020)
data <- rlnorm(100, meanlog = 1, sdlog = 1)

library(MASS)

f <- fitdistr(data, "lognormal")
f$estimate

p <- pretty(range(data))
x <- seq(from = min(p), to = max(p), by = 0.1)

hist(data, freq = FALSE)
lines(x, y = dlnorm(x,
                     meanlog = f$estimate["meanlog"],
                     sdlog = f$estimate["sdlog"])
)


Hope this helps,

Rui Barradas


Às 13:12 de 21/01/21, Marc Girondot via R-help escreveu:
> Two solutions not exactly equivalent ;
> 
> data <- rlnorm(100, meanlog = 1, sdlog = 1)
> histdata <- hist(data, ylim=c(0, 100))
> library(MASS)
> 
> f <- fitdistr(data, "lognormal")
> 
> f$estimate
> 
> lines(x=seq(from=0, to=50, by=0.1),
>   � y=dlnorm(x=seq(from=0, to=50, by=0.1), meanlog =
> f$estimate["meanlog"], sdlog = f$estimate["sdlog"])*400
> )
> 
> library(HelpersMG)
> 
> m <- modeled.hist(breaks=histdata$breaks, FUN=plnorm,
>   ����������������������������� meanlog = f$estimate["meanlog"], sdlog =
> f$estimate["sdlog"], sum = 100)
> 
> points(m$x, m$y, pch=19, col="red")
> 
> Marc Girondot
> 
> Le 21/01/2021 � 12:54, Eric Leroy a �crit�:
>> Hi,
>>
>> I would like to plot the histogram of data and fit it with a lognormal
>> distribution.
>>
>> The ideal, would be to superimpose the fit on the histogram and write
>> the results of the fit on the figure.
>>
>> Right now, I was able to plot the histogram and fit the density with a
>> lognormal, but I can't combine all together.
>>
>> Here is the code I wrote :
>>
>> histdata <- hist(dataframe$data)
>>
>> library(MASS)
>>
>> fitdistr(histdata$density, "lognormal")
>>
>> Can you help me ?
>>
>> Best regards,
>>
>>
>> ______________________________________________
>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> 
> 
> 
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> 
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>