[R] multiple graphs on one plot

[Andrew Halford]

Hi Jim,

Many thanks for your help and yes CW is carapace width. Here is the final
coding I used...I set the peak of the curves at max frequency bin for each
sex. I also added the means and SD's from my data. According to my visual
diagnostics (qqplots, density plots) the frequency distributions do appear
normally distributed in this case. To be honest Ive struggled to find
whether CW is normally distributed in mud crab populations or not.


f<- lf_crabs$cw[lf_crabs$sex=='female']
m<- lf_crabs$cw[lf_crabs$sex=='male']

# find mean and sd to determine normal curve dimensions
m_m <-mean(m)
sd_m <-sqrt(var(m))
m_f <-mean(f)
sd_f <-sqrt(varf(f))

mf <- list(f,m)
multhist(mf, xlab="CW", ylab="Frequency", ylim=c(0,100),main="All Measured
Crabs", col=c("dark gray", "light gray"),
         breaks=seq(90,210, by=10),beside=TRUE,space=c(0,0.5))
legend("topright", c("Females", "Males"), fill=c("dark gray", "light gray"))
lines(seq(0,32,length.out=121),rescale(dnorm(90:210,145.4867,20.99906),c(0,50)),col="dark
gray",lwd=2)
lines(seq(0,32,length.out=121),rescale(dnorm(90:210,151.0783,21.88299),c(0,80)),col="light
gray",lwd=2)
abline(v=145.4867,lwd=2,col="red")

On Mon, 13 May 2019 at 17:30, Jim Lemon <drjimlemon using gmail.com> wrote:

> Hi Andrew,
> First, a little mind reading. My crystal ball says that "cw" can be
> interpreted as "carapace width". It didn't tell me the parameters of
> the distribution, so:
>
> set.seed(1234)
> mf<-list(rnorm(400,145,15),rnorm(400,160,15))
> library(plotrix)
> multhist(mf, xlab="CW", ylab="Frequency", ylim=c(0,100),main="All Measured
> Crabs", col=c("dark gray", "light gray"),
>          breaks=seq(90,210, by=10),beside=TRUE,space=c(0,0.5))
> legend("topright", c("Females", "Males"), fill=c("dark gray", "light
> gray"))
> lines(seq(0,32,length.out=121),rescale(dnorm(90:210,145,15),c(0,100)))
>
> This produces what I think you are after. Note that it may be
> misleading as the distribution of carapace width in real mud crabs
> doesn't look normal to me.
>
> Jim
>
> On Mon, May 13, 2019 at 3:00 PM Andrew Halford <andrew.halford using gmail.com>
> wrote:
> >
> > Hi Listers
> >
> > I've been trying to make a single graphic that has frequency histograms
> for
> > male and female mud crabs displayed side by side (such as when using the
> > beside=TRUE command for barplots). I then want to display a normal
> > distribution on top of the male and female histograms.
> >
> > I have been using the multhist command in Plotrix to generate the
> > histograms without too much problem, but I cannot get the normal
> > distributions to plot up on the same graph.
> >
> > Histograms plot
> >
> > mf <-
> >
> list(lf_crabs$cw[lf_crabs$sex=='female'],lf_crabs$cw[lf_crabs$sex=='male'])
> > multhist(mf, xlab="CW", ylab="Frequency", ylim=c(0,100),main="All
> Measured
> > Crabs", col=c("dark gray", "light gray"),
> >          breaks=seq(90,210, by=10),beside=TRUE,space=c(0,0.5))
> > legend("topright", c("Females", "Males"), fill=c("dark gray", "light
> gray"))
> >
> > Then I try to add a normal distribution curve just to the female data
> but I
> > cant get the output to plot
> >
> > points(seq(min(mf[[1]]), max(mf[[1]]), length.out=300),
> >        dnorm(seq(min(mf[[1]]), max(mf[[1]]), length.out=300),
> >              mean(mf[[1]]), sd(mf[[1]])),type="l", col="dark gray")
> >
> > Even trying to add an abline to the plot doesn't work.
> >
> > What am I missing?
> >
> > cheers
> >
> > Andy
> >
> > --
> > Andrew Halford Ph.D
> > Senior Coastal Fisheries Scientist
> > Pacific Community | Communauté du Pacifique CPS – B.P. D5 | 98848 Noumea,
> > New Caledonia | Nouméa, Nouvelle-Calédonie
> >
> >         [[alternative HTML version deleted]]
> >
> > ______________________________________________
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>


-- 
Andrew Halford Ph.D
Senior Coastal Fisheries Scientist
Pacific Community | Communauté du Pacifique CPS – B.P. D5 | 98848 Noumea,
New Caledonia | Nouméa, Nouvelle-Calédonie

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