Combining output from smatr with ggplot2 - r

I have a dataset of leaf trait measurements made at multiple sites at two contrasting seasons. I am interested to explore the association/line fit between a pair of traits and to differentiate the seasons at each site.
Rather than a linear regression, I would prefer to use the Standardised Major Axis approach within the smatr package:
e.g. sma.site1 <- sma(TraitA ~ TraitB * Visit, data=subset(myfile, Site=="Site1")) # testing the null hypothesis of common slopes for the two Visits (Seasons) at a given Site.
I can produce a handy lattice plot in ggplot2 with a separate panel for each Site and the points differentiated by Visit:
e.g. qplot(TraitB, TraitA, data=myfile, colour=Visit) + facet_wrap(~Site, ncol=2)
However, if I add trend lines fitted with the additional argument in ggplot2:
+ geom_smooth(aes(group=Visit), method="lm", se=F)
……, those lines are not a good match for the sma coefficients.
What I would like to do is fit the lines suggested by the sma test onto the ggplot lattice. Is there an easy, or efficient, way to do that?
I know that I can subset the data, produce a plot for each site, add the relevant lines with + geom_abline() and then stitch the separate plots up together with grid.arrange(). But that feels very long-winded.
I would be grateful for any pointers.

I don't know anything about the smatr package but you should be able to tweak this to get the right values. Since you provided no data I used the leaf data from the example in the pkg. The basic idea is to pull out the slope & intercept from the returned sma object and then facet the geom_abline. I may be misinterpreting the object, though.
library(smatr)
library(ggplot2)
data(leaflife)
do.call(rbind, lapply(unique(leaflife$site), function(x) {
obj <- sma(longev~lma*rain, data=subset(leaflife, site=x))
data.frame(site=x,
intercept=obj$coef[[1]][1, 1],
slope=obj$coef[[1]][2, 1])
})) -> fits
gg <- ggplot(leaflife)
gg <- gg + geom_point(aes(x=lma, y=longev, color=soilp))
gg <- gg + geom_abline(data=fits, aes(slope=slope, intercept=intercept))
gg <- gg + facet_wrap(~site, ncol=2)
gg

I just saw this question and am not sure if you are still interested in this. I run the code by hrbrmstr, and found actually the only thing you need to change is:
obj <- sma(longev~lma*rain, data=subset(leaflife, site == x))
then you can get the plot with four lines for each group.
and also

Related

Plotting a subset of envfit results onto an ordination

I'm working on a figure for a publication where we are looking at a combination of plant coverage and other environmental data on differing communities. I am trying to make a multi-panel figure, with panels that display all the envfit results, one that displays only the plants, and one that displays only the other enviro. Because of the complexity of the figure, it's actually a little easier to construct in the base plot function than in ggvegan.
My challenge is figuring out how to subset the results of the envfit analysis object for the different panels. A simplified example would be:
library(vegan)
data("mite")
data("mite.env")
set.seed(55)
nmds<-metaMDS(mite)
set.seed(55)
ef<-envfit(nmds, mite.env, permu=999)
plot(ef, p.max = .05)
which produces this figure
For sake of the example, does anyone have suggestions on a way I could create two separate figures, one with only the WatrCont vector and one with only the SubsDens vector? I'm sure there is a way to pull specific results out of the ef object, but my coding is not savvy enough to understand how.
Additionally, is there a way to have the jumble of text at the center not overlap, similar to jitter in ggplot?
Thank y'all for all of your help!
I would suggest extracting the data from nmds and ef and using ggplot to add the required elements to your plots.
Here is an example:
library(vegan)
library(ggplot2)
data("mite")
data("mite.env")
set.seed(55)
nmds<-metaMDS(mite)
set.seed(55)
ef<-envfit(nmds, mite.env, permu=999)
# Get the NMDS scores
nmds_values <- as.data.frame(scores(nmds))
# Get the coordinates of the vectors produced for continuous predictors in your envfit
vector_coordinates <- as.data.frame(scores(ef, "vectors")) * ordiArrowMul(ef)
# Plot the vectors separately
ggplot(nmds_values,
aes(x=NMDS1, y = NMDS2)) +
geom_point() +
geom_segment(aes(x=0, y=0, xend=NMDS1, yend=NMDS2),
vector_coordinates[1,]) +
geom_text(aes(x=NMDS1,y=NMDS2),
vector_coordinates[1,],
label=row.names(vector_coordinates[1,]))
ggplot(nmds_values,
aes(x=NMDS1, y = NMDS2)) +
geom_point() +
geom_segment(aes(x=0, y=0, xend=NMDS1, yend=NMDS2),
vector_coordinates[2,]) +
geom_text(aes(x=NMDS1,y=NMDS2),
vector_coordinates[2,],
label=row.names(vector_coordinates[2,]))
You can play around with the colours, size of the different elements as you see fit. Coordinates for categorical predictors can be extracted in a similar manner.

how to plot only most abundant species in NMDS?

I need to plot an ordination plot showing only let s say the 20 most abundant species.
I tried to do the sum of the species colunm and then select only a certain sum value:
abu <- colSums(dune)
abu
sol <- metaMDS(dune)
sol
plot(sol, type="text", display="species", select = abu > 40)
I get this error: select is not a graphical parameter
I would expect to see only small number of species but it does not happen,
how do you show only a small number of species in the NMDS plot?
This is not straightforward. You are getting an error because select is not a parameter for the plot. Unfortunately, the result of the analysis is not a data.frame that could be handled easily (e.g. with tidyverse), and even more unfortunately, the plot() function called is not your standard plot, but a method defined specifically for objects of this class. The authors of this method did not foresee your need, and therefore, we must make the plot manually. But to do that, we need to understand what is plotting and how.
Let us find out more about the object sol:
class(sol)
# [1] "metaMDS" "monoMDS"
methods(class="metaMDS")
# [1] goodness nobs plot points print scores sppscores<- text
Oh good, we have a plot method. After a moment of digging, we find it in the vegan package (not exported, so we need to access it via vegan:::plot.metaMDS). It appears to be a wrapper around a function called ordiplot. We edit the function with edit() to figure out what it is doing. Essentially, it boils down to the following (with loads of unnecessary code):
Y <- scores(sol, display="species")
plot(Y, type="n")
text(Y[,1], Y[,2], rownames(Y), col="red")
This is, more or less, your plot. Choosing the species to show is now trivial, but first we must make sure that rows of Y are in the same order as columns of dune:
all(colnames(dune) == rownames(Y))
Y.sel <- Y[colSums(dune) > 40, ]
plot(Y.sel[,1], Y.sel[,2], type="n", xlim=c(-.8, .8), ylim=c(-.4, .4))
text(Y.sel[,1], Y.sel[,2], rownames(Y.sel), col="red")
We can of course make a much nicer plot. For example, with ggplot (it is definitely possible to make a much nicer plot with base R as well). We could actually show the abundance of the plants using the size esthetics:
library(ggplot2)
library(ggrepel)
Y <- data.frame(Y)
Y$abundance <- colSums(dune)
Y$labels <- rownames(Y)
ggplot(Y, aes(x=NMDS1, y=NMDS2, size=abundance)) +
geom_point() + geom_text_repel(aes(label=labels)) +
theme_minimal()
To filter the species by abundance, we now can do the following:
library(tidyverse)
Y %>% filter(abundance > 40) %>%
ggplot(Y, aes(x=NMDS1, y=NMDS2, size=abundance)) +
geom_point() + geom_text_repel(aes(label=labels)) +
theme_minimal()

selecting only some facets to print in facet_wrap, ggplot2

my question is very simple, but I have failed to solve it after many attempts. I just want to print some facets of a facetted plot (made with facet_wrap in ggplot2), and remove the ones I am no interested in.
I have facet_wrap with ggplot2, as follows:
#anomalies linear trends
an.trends <- ggplot()+
geom_smooth(method="lm", data=tndvilong.anomalies, aes(x=year, y=NDVIan, colour=TenureZone,
group=TenureZone))+
scale_color_manual(values=miscol) +
ggtitle("anomalies' trends")
#anomalies linear trends by VEG
an.trendsVEG <- an.trends + facet_wrap(~VEG,ncol=2)
print(an.trendsVEG)
And I get the plot as I expected (you can see it in te link below):
anomalies' trends by VEG
The question is: how do I get printed only the facest I am interested on?
I only want to print "CenKal_ShWoodl", "HlShl_ShDens", "NKal_ShWoodl", and "ThShl_ShDens"
Thanks
I suggest the easiest way to do that is to simply give ggplot() an appropriate subset. In this case:
facets <- c("CenKal_ShWoodl", "HlShl_ShDens", "NKal_ShWoodl", "ThShl_ShDens")
an.trends.sub <- ggplot(tndvilong.anomalies[tndvilong.anomalies$VEG %in% facets,])+
geom_smooth(method="lm" aes(x=year, y=NDVIan, colour=TenureZone,
group=TenureZone))+
scale_color_manual(values=miscol) +
ggtitle("anomalies' trends") +
facet_wrap(~VEG,ncol=2)
Obviously without your data I can't be sure this will give you what you want, but based on your description, it should work. I find that with ggplot, it is generally best to pass it the data you want plotted, rather than finding ways of changing the plot itself.

R: Plot multiple box plots using columns from data frame

I would like to plot an INDIVIDUAL box plot for each unrelated column in a data frame. I thought I was on the right track with boxplot.matrix from the sfsmsic package, but it seems to do the same as boxplot(as.matrix(plotdata) which is to plot everything in a shared boxplot with a shared scale on the axis. I want (say) 5 individual plots.
I could do this by hand like:
par(mfrow=c(2,2))
boxplot(data$var1
boxplot(data$var2)
boxplot(data$var3)
boxplot(data$var4)
But there must be a way to use the data frame columns?
EDIT: I used iterations, see my answer.
You could use the reshape package to simplify things
data <- data.frame(v1=rnorm(100),v2=rnorm(100),v3=rnorm(100), v4=rnorm(100))
library(reshape)
meltData <- melt(data)
boxplot(data=meltData, value~variable)
or even then use ggplot2 package to make things nicer
library(ggplot2)
p <- ggplot(meltData, aes(factor(variable), value))
p + geom_boxplot() + facet_wrap(~variable, scale="free")
From ?boxplot we see that we have the option to pass multiple vectors of data as elements of a list, and we will get multiple boxplots, one for each vector in our list.
So all we need to do is convert the columns of our matrix to a list:
m <- matrix(1:25,5,5)
boxplot(x = as.list(as.data.frame(m)))
If you really want separate panels each with a single boxplot (although, frankly, I don't see why you would want to do that), I would instead turn to ggplot and faceting:
m1 <- melt(as.data.frame(m))
library(ggplot2)
ggplot(m1,aes(x = variable,y = value)) + facet_wrap(~variable) + geom_boxplot()
I used iteration to do this. I think perhaps I wasn't clear in the original question. Thanks for the responses none the less.
par(mfrow=c(2,5))
for (i in 1:length(plotdata)) {
boxplot(plotdata[,i], main=names(plotdata[i]), type="l")
}

Creating a facet_wrap plot with ggplot2 with different annotations in each plot

I am using ggplot2 to explore the result of some testing on an agent-based model. The model can end in one of three rounds per realization, and as such I am interested in how player utilities differ in terms of what round the game ends and their relative position in 2D space.
All this is to say that I have generated a facet_wrap plot to show this for each round, but I would also like to annotate each plot with the cor(x,y) for the subset of data represented in each facet. Is there a way to tell ggplot2 that I would like the annotation to use the subset of data generated by facet_wrap? Here is the code I have so far, and what it is producing
library(ggplot2)
# Load data
abm.data<-read.csv("ABM_results.csv")
# Create new colun for area of Pareto set
attach(abm.data)
area<-abs(((x3*(y2-y1))+(x2*(y1-y3))+(x1*(y3-y2)))/2)
abm.data<-transform(abm.data,area=area)
detach(abm.data)
# Compare area of Pareto set with player utility
png("area_p1.png",res=100,pointsize=20,height=500,width=1600)
area.p1<-ggplot(abm.data,aes(x=area))+geom_point(aes(y=U1_2,colour="Player 1",alpha=0.4))+facet_wrap(~round,ncol=3)+
annotate("text",0.375,-1.25,label=paste("rho=",round(cor(abm.data$area,abm.data$U1_2),2)), parse=TRUE)+
scale_colour_manual(values=c("Player 1"="red"))
area.p1+xlab("Area of Pareto Set")+ylab("Player Utility at Game End")+
opts(title="Final Player 1 Utility by Pareto Set Size and Round Game Ends",legend.position="none")
dev.off()
(source: drewconway.com)
As you can see, there are two problems:
The \rho value is of the full dataset, rather than the subsets by 'round'. Is there a way to get the cor(x,y) to print based on only the data shown in each plot?
The annotation should read "\rho=some_value" but instead I get "=(\rho,value);" is there a way to fix this?
To fix the second problem use
annotate("text", 0.375, -1.25,
label=paste("rho==", round(cor(abm.data$area, abm.data$U1_2), 2)),
parse=TRUE)
i.e. "rho==".
Edit: Here is a solution to solve the first problem
library("plyr")
library("ggplot2")
set.seed(1)
df <- data.frame(x=rnorm(300), y=rnorm(300), cl=gl(3,100)) # create test data
df.cor <- ddply(df, .(cl), function(val) sprintf("rho==%.2f", cor(val$x, val$y)))
p1 <- ggplot(data=df, aes(x=x)) +
geom_point(aes(y=y, colour="col1", alpha=0.4)) +
facet_wrap(~ cl, ncol=3) +
geom_text(data=df.cor, aes(x=0, y=3, label=V1), parse=TRUE) +
scale_colour_manual(values=c("col1"="red")) +
opts(legend.position="none")
print(p1)
The same question may be asked as for adding segments for each facet. We can solve these general problems by geom_segment instead of annotate("segment",...), for the geom_foo, we can define a data.frame to store the data for the geom_foo.

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