Prevent plot.gam from producing a figure - r

Say, I have a GAM that looks like this:
# Load library
library(mgcv)
# Load data
data(mtcars)
# Model for mpg
mpg.gam <- gam(mpg ~ s(hp) + s(wt), data = mtcars)
Now, I'd like to plot the GAM using ggplot2. So, I use plot.gam to produce all the information I need, like this:
foo <- plot(mpg.gam)
This also generates an unwanted figure. (Yes, I realise that I'm complaining that a plotting function plots something...) When using visreg in the same way, I'd simply specify plot = FALSE to suppress the figure, but plot.gam doesn't seem to have this option. My first thought was perhaps invisible would do the job (e.g., invisible(foo <- plot(mpg.gam))), but that didn't seem to work. Is there an easy way of doing this without outputting the unwanted figure to file?

Okay, so I finally figured it out 5 minutes after posting this. There is an option to select which term to plot (e.g., select = 1 is the first term, select = 2 is the second), although the default behaviour is to plot all terms. If, however, I use select = 0 it doesn't plot anything and doesn't give an error, yet returns exactly the same information. Check it out:
# Load library
library(mgcv)
# Load data
data(mtcars)
# Model for mpg
mpg.gam <- gam(mpg ~ s(hp) + s(wt), data = mtcars)
# Produces figures for all terms
foo1 <- plot(mpg.gam)
# Doesn't produce figures
foo2 <- plot(mpg.gam, select = 0)
# Compare objects
identical(foo1, foo2)
[1] TRUE
Bonza!

Related

Set common y axis limits from a list of ggplots

I am running a function that returns a custom ggplot from an input data (it is in fact a plot with several layers on it). I run the function over several different input data and obtain a list of ggplots.
I want to create a grid with these plots to compare them but they all have different y axes.
I guess what I have to do is extract the maximum and minimum y axes limits from the ggplot list and apply those to each plot in the list.
How can I do that? I guess its through the use of ggbuild. Something like this:
test = ggplot_build(plot_list[[1]])
> test$layout$panel_scales_x
[[1]]
<ScaleContinuousPosition>
Range:
Limits: 0 -- 1
I am not familiar with the structure of a ggplot_build and maybe this one in particular is not a standard one as it comes from a "custom" ggplot.
For reference, these plots are created whit the gseaplot2 function from the enrichplot package.
I dont know how to "upload" an R object but if that would help, let me know how to do it.
Thanks!
edit after comments (thanks for your suggestions!)
Here is an example of the a gseaplot2 plot. GSEA stands for Gene Set Enrichment Analysis, it is a technique used in genomic studies. The gseaplot2 function calculates a running average and then plots it and another bar plot on the bottom.
and here is the grid I create to compare the plots generated from different data:
I would like to have a common scale for the "Running Enrichment Score" part.
I guess I could try to recreate the gseaplot2 function and input all of the datasets and then create the grid by facet_wrap, but I was wondering if there was an easy way of extracting parameters from a plot list.
As a reproducible example (from the enrichplot package):
library(clusterProfiler)
data(geneList, package="DOSE")
gene <- names(geneList)[abs(geneList) > 2]
wpgmtfile <- system.file("extdata/wikipathways-20180810-gmt-Homo_sapiens.gmt", package="clusterProfiler")
wp2gene <- read.gmt(wpgmtfile)
wp2gene <- wp2gene %>% tidyr::separate(term, c("name","version","wpid","org"), "%")
wpid2gene <- wp2gene %>% dplyr::select(wpid, gene) #TERM2GENE
wpid2name <- wp2gene %>% dplyr::select(wpid, name) #TERM2NAME
ewp2 <- GSEA(geneList, TERM2GENE = wpid2gene, TERM2NAME = wpid2name, verbose=FALSE)
gseaplot2(ewp2, geneSetID=1, subplots=1:2)
And this is how I generate the plot list (probably there is a much more elegant way):
plot_list = list()
for(i in 1:3) {
fig_i = gseaplot2(ewp2,
geneSetID=i,
subplots=1:2)
plot_list[[i]] = fig_i
}
ggarrange(plotlist=plot_list)

Plot LOESS (STL) decomposition using Ggvis

I want to be able to plot the three different elements of The Seasonal Trend Decomposition using Loess (STL) with Ggvis.
However, I recive this error:
Error: data_frames can only contain 1d atomic vectors and lists
I am using the nottem data set.
# The Seasonal Trend Decomposition using Loess (STL) with Ggvis
# Load nottem data set
library(datasets)
nottem <- nottem
# Decompose using stl()
nottem.stl = stl(nottem, s.window="periodic")
# Plot decomposition
plot(nottem.stl)
Now, this is the information I am interested in. In order to make this into a plot that I can play around with I transform this into a data frame using the xts-package. So far so good.
# Transform nottem.stl to a data.frame
library(xts)
df.nottem.stl <- as.data.frame(as.xts(nottem.stl$time.series))
# Add date to data.frame
df.nottem.stl$date <- data.frame(time = seq(as.Date("1920-01-01"), by = ("months"), length =240))
# Glimpse data
glimpse(df.nottem.stl)
# Plot simple line of trend
plot(df.nottem.stl$date, df.nottem.stl$trend, type = "o")
This is pretty much the plot I want. However, I want to be able to use it with Shiny and therefore Ggvis is preferable.
# Plot ggvis
df.nottem.stl%>%
ggvis(~date, ~trend)%>%
layer_lines()
This is where I get my error.
Any hints on what might go wrong?
First of all your df.nottem.stl data.frame contains a Date data.frame, so you should be using the date$time column. Then using the layer_paths function instead of the layer_lines will make it work. I always find layer_paths working better than layer_lines:
So this will work:
library(ggvis)
df.nottem.stl%>%
ggvis(~date$time, ~trend)%>%
#for points
layer_points() %>%
#for lines
layer_paths()
Output:

How to control plot layout for lmerTest output results?

I am using lme4 and lmerTest to run a mixed model and then use backward variable elimination (step) for my model. This seems to work well. After running the 'step' function in lmerTest, I plot the final model. The 'plot' results appear similar to ggplot2 output.
I would like to change the layout of the plot. The obvious answer is to do it manually myself creating an original plot(s) with ggplot2. If possible, I would like to simply change the layout of of the output, so that each plot (i.e. plotted dependent variable in the final model) are in their own rows.
See below code and plot to see my results. Note plot has three columns and I would like three rows. Further, I have not provided sample data (let me know if I need too!).
library(lme4)
library(lmerTest)
# Full model
Female.Survival.model.1 <- lmer(Survival.Female ~ Location + Substrate + Location:Substrate + (1|Replicate), data = Transplant.Survival, REML = TRUE)
# lmerTest - backward stepwise elimination of dependent variables
Female.Survival.model.ST <- step(Female.Survival.model.1, reduce.fixed = TRUE, reduce.random = FALSE, ddf = "Kenward-Roger" )
Female.Survival.model.ST
plot(Female.Survival.model.ST)
The function that creates these plots is called plotLSMEANS. You can look at the code for the function via lmerTest:::plotLSMEANS. The reason to look at the code is 1) to verify that, indeed, the plots are based on ggplot2 code and 2) to see if you can figure out what needs to be changed to get what you want.
In this case, it sounds like you'd want facet_wrap to have one column instead of three. I tested with the example from the **lmerTest* function step help page, and it looks like you can simply add a new facet_wrap layer to the plot.
library(ggplot2)
plot(Female.Survival.model.ST) +
facet_wrap(~namesforplots, scales = "free", ncol = 1)
Try this: plot(difflsmeans(Female.Survival.model.ST$model, test.effs = "Location "))

rCharts Polychart: Adding horizontal or vertical lines to a plot

I'm having some trouble understanding how to customize graphs using the rPlot function in the rCharts Package. Say I have the following code
#Install rCharts if you do not already have it
#This will require devtools, which can be downloaded from CRAN
require(devtools)
install_github('rCharts', 'ramnathv')
#simulate some random normal data
x <- rnorm(100, 50, 5)
y <- rnorm(100, 30, 2)
#store in a data frame for easy retrieval
demoData <- data.frame(x,y)
#generate the rPlot Object
demoChart <- rPlot(y~x, data = demoData, type = 'point')
#return the object // view the plot
demoChart
This will generate a plot and that is nice, but how would I go about adding horizontal lines along the y-axis? For example, if I wanted to plot a green line which represented the average y-value, and then red lines which represented +/- 3 standard deviations from the average? If anybody knows of some documentation and could point me to it then that would be great. However, the only documentation I could find was on the polychart.js (https://github.com/Polychart/polychart2) and I'm not quite sure how to apply this to the rCharts rPlot function in R.
I have done some digging and I feel like the answer is going to have something to do with adding/modifying the layers parameter within the rPlot object.
#look at the slots in this object
demoChart$params$layers
#doing this will return the following output (which will be different for
#everybody because I didn't set a seed). Also, I removed rows 6:100 of the data.
demoChart$params$layers
[[1]]
[[1]]$x
[1] "x"
[[1]]$y
[1] "y"
[[1]]$data
x y
1 49.66518 32.75435
2 42.59585 30.54304
3 53.40338 31.71185
4 58.01907 28.98096
5 55.67123 29.15870
[[1]]$facet
NULL
[[1]]$type
[1] "point"
If I figure this out I will post a solution, but I would appreciate any help/advice in the meantime! I don't have much experience playing with objects in R. I feel like this is supposed to have some similarity to ggplot2 which I also don't have much experience with.
Thanks for any advice!
You can overlay additional graphs onto your rCharts plot using layers. Add values for any additional layers as columns on to your original data.frame. copy_layer lets you use the values from the data.frame in the extra layers.
# Regression Plots using rCharts
require(rCharts)
mtcars$avg <- mean(mtcars$mpg)
mtcars$sdplus <- mtcars$avg + sd(mtcars$mpg)
mtcars$sdneg <- mtcars$avg - sd(mtcars$mpg)
p1 <- rPlot(mpg~wt, data=mtcars, type='point')
p1$layer(y='avg', copy_layer=T, type='line', color=list(const='red'))
p1$layer(y='sdplus', copy_layer=T, type='line', color=list(const='green'))
p1$layer(y='sdneg', copy_layer=T, type='line', color=list(const='green'))
p1
Here are a couple of examples: one from the main rCharts website and the other showing how to overlay a regression line.

Getting statistics for nodes from a regression tree in the party pagckage

I am using the party package in R.
I would like to get various statistics (mean, median, etc) from various nodes of the resultant tree, but I cannot see how to do this. For example
airq <- subset(airquality, !is.na(Ozone))
airct <- ctree(Ozone ~ ., data = airq,
controls = ctree_control(maxsurrogate = 3))
airct
plot(airct)
results in a tree with 4 terminal nodes. How would I get the mean airquality for each of those nodes?
I can't get which variable of the node is the airquality. But I show you here how to customize your tree plot:
innerWeights <- function(node){
grid.circle(gp = gpar(fill = "White", col = 1))
mainlab <- node$psplit$variableName
label <- paste(mainlab,paste('prediction=',round(node$prediction,2) ,sep= ''),sep= '\n')
grid.text( label= label,gp = gpar(col='red'))
}
plot(airct, inner_panel = innerWeights)
Edit to get statistics by node
library(gridExtra)
innerWeights <- function(node){
dat <- round_any(node$criterion$statistic,0.01)
grid.table(t(dat))
}
plot(airct, inner_panel = innerWeights)
This is surprisingly harder than I thought. Try something like this:
a <- by(airq,where(airct),colMeans) #or whatever function you desire for colMeans
a
a$"3" #access at node three
a[["3"]] #same thing
You might find some other useful examples with ?`BinaryTree-class`.
How to get there if you are lost in R-space (and the documentation does not help you immediately)
First, try str(airct): The output is a bit lengthy, since the results are complex, but for easier cases, e.g. t-test, this is all you need.
Since print(airct) or simply airct gives quite useful info, how does print work? Try class(airct) or check the documentation: The result if of class BinaryTree.
Ok, we could have seen this from the docs, and in this case the information on the BinaryTree page is good enough (see the examples on that page.)
But assume the author was lazy: the try getAnywhere(print.BinaryTree). On the top you find y<-x#responses: So try airct#responses next
You can also do this using the dplyr package.
First get which node each observation belongs to and store it in the dataframe.
airq$node <- where(airct)
Then use group_by to group the observations by node, and use summarise to calculate the mean of the Ozone measurement. You can swap mean out for whatever summary statistic function you like.
airq %>% group_by(node) %>% summarise(avg=mean(Ozone))
Which gives the following results.
node avg
(int) (dbl)
1 3 55.60000
2 5 18.47917
3 6 31.14286
4 8 81.63333
5 9 48.71429

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