Transforming the y-axis without changing raw data in ggplot2 - r

I have a question about how to transform the y-axis in ggplot2. My plot now has two lines and a scatter plot. For the scatter plot, I am very interested in the area around zero. Is there a possible way to enlarge the space between 0% and 5% and narrow the space between 20% and 30%?
I have tried to use coord_trans(y = "log10") to transform into a log form. But in this case, I have a lot of negative values, so if I want to use sqrt or log, the negative values will be removed. Do you have any suggestions?
Example of data points:
df1 = data.frame(y = runif(200,min = -1, max = 1))
df1 = data.frame( x= seq(1:200), y = df1[order(abs(df1$y)),])
ggplot(df1) +
geom_point(colour = "black",aes(x,y) ,size = 0.1)
I want to have more space between 0% and 5 % and less space between 5% and 30%.
I have tried to use trans_new() to transform the axes.
eps <- 1e-8
tn <- trans_new("logpeps",
function(x) (x+eps)^(3),
function(y) ((y)^(1/3) ),
domain=c(- Inf, Inf)
)
ggplot(df1)+ geom_point(colour = "black",aes(x,y) ,size = 0.1) +
# xlab("Observations sorted by PD in v3.1") + ylab("Absolute PD difference ") +
# ggtitle("Absolute PD for RiskCalc v4.0 relative to v3.1") +
scale_x_continuous(breaks = seq(0, round(rownum/1000)*1000, by = round(rownum/100)*10)) +
scale_y_continuous(limits = c(-yrange,yrange),breaks = c(-breaksY,breaksY),
sec.axis = sec_axis(~.,breaks = c(-breaksY[2:length(breaksY)],breaksY), labels = scales:: percent
)) +
# geom_line(data = df, aes(x,y[,3], colour = "blue"),size = 1) +
# geom_line(data = ds,aes(xval, yval,colour = "red"),size = 1) +
coord_trans(y = tn) +
scale_color_discrete(name = element_blank())
But it compresses the plot to the center, which is opposite to what I want. Then I try to use y = y^3, but it shows an
ERROR: zero_range(range)

Try a cube root transform on the y values:
aes(y=yVariable^(1/3))
or use trans_new() to define a new transformation (such as cube root, with pleasing breaks and labels).

A couple thoughts:
You can remove the empty edges of the plot like so:
scale_y_continuous(expand = c(0,0))
If you want to try the log transformation, just do:
scale_y_log10()
If you want to focus the window:
scale_y_continuous(limits=c(-.15,.15), expand=c(0,0))
Also consider adding theme_bw() for a cleaner look

Related

Expanding confidence interval in R ggplots using coord_cartesian -- not working [duplicate]

my ggplot R-code works perfectly ok with my other datasets but I'm stumbled with why it's not working for one particular data set. See image below where the filled confidence interval stops at 0.10:
For reproducing the problem:
library(nlme)
library(ggeffects)
library(ggplot2)
SurfaceCoverage <- c(0.02,0.04,0.06,0.08,0.1,0.12,0.02,0.04,0.06,0.08,0.1,0.12)
SpecificSurfaceEnergy <- c(18.0052997,15.9636971,14.2951057,13.0263081,13.0816591,13.3825573,2.9267577,2.2889628,1.8909175,1.0083036,0.5683574,0.1681063)
sample <- c(1,1,1,1,1,1,2,2,2,2,2,2)
highW <- data.frame(sample,SurfaceCoverage,SpecificSurfaceEnergy)
highW$sample <- sub("^", "Wettable", highW$sample)
highW$RelativeHumidity <- "High relative humidity"; highW$group <- "Wettable"
highW$sR <- paste(highW$sample,highW$RelativeHumidity)
dfhighW <- data.frame(
"y"=c(highW$SpecificSurfaceEnergy),
"x"=c(highW$SurfaceCoverage),
"b"=c(highW$sample),
"sR"=c(highW$sR)
)
mixed.lme <- lme(y~log(x),random=~1|b,data=dfhighW)
pred.mmhighW <- ggpredict(mixed.lme, terms = c("x"))
(ggplot(pred.mmhighW) +
geom_line(aes(x = x, y = predicted)) + # slope
geom_ribbon(aes(x = x, ymin = predicted - std.error, ymax = predicted + std.error),
fill = "lightgrey", alpha = 0.5) + # error band
geom_point(data = dfhighW, # adding the raw data (scaled values)
aes(x = x, y = y, shape = b)) +
xlim(0.01,0.2) +
ylim(0,30) +
labs(title = "") +
ylab(bquote('Specific Surface Energy ' (mJ/m^2))) +
xlab(bquote('Surface Coverage ' (n/n[m]) )) +
theme_minimal()
)
Can someone advise me how to fix this? Thanks.
The last part of your ribbon has disappeared because you have excluded it from the plot. The lower edge of your ribbon is the following vector:
pred.mmhighW$predicted - pred.mmhighW$std.error
#> [1] 3.91264018 2.37386628 1.47061258 0.82834206 0.32935718 -0.07886245
Note the final value is a small negative number, but you have set the y axis limits with:
ylim(0, 30)
So anything negative will be cut off. If you change to
ylim(-2, 30)
You get
I don't know whether this is already answered previously, but coord_cartesian and scales::squish are two solutions to this problem.
coord_cartesian adjusts the viewport without adjusting the spacing of grid lines etc. (unlike xlim()/scale_*_continuous(limits = ...), which will "zoom")
scales::squish() is suboptimal if you are "squishing" lines and points, not just edgeless polygons (in the case of fill/polygons, squishing and clipping produce the same results)
gg0 <- (ggplot(pred.mmhighW)
+ geom_ribbon(aes(x = x, ymin = predicted - std.error,
ymax = predicted + std.error),
fill = "lightgrey", alpha = 0.5)
+ theme_minimal()
)
## set lower limit to 5 for a more obvious effect
gg0 + coord_cartesian(ylim = c(5, 30))
gg0 + scale_y_continuous(limits = c(5, 30),
## oob = "out of bounds" behaviour
oob = scales::squish)

ggplot2: Projecting points or distribution on a non-orthogonal (eg, -45 degree) axis

The figure below is a conceptual diagram used by Michael Clark,
https://m-clark.github.io/docs/lord/index.html
to explain Lord's Paradox and related phenomena in regression.
My question is framed in this context and using ggplot2 but it is broader in terms of geometry & graphing.
I would like to reproduce figures like this, but using actual data. I need to know:
how to draw a new axis at the origin, with a -45 degree angle, corresponding to values of y-x
how to draw little normal distributions or density diagrams, or other representations of the values y-x projected onto this axis.
My minimal base example uses ggplot2,
library(ggplot2)
set.seed(1234)
N <- 200
group <- rep(c(0, 1), each = N/2)
initial <- .75*group + rnorm(N, sd=.25)
final <- .4*initial + .5*group + rnorm(N, sd=.1)
change <- final - initial
df <- data.frame(id = factor(1:N),
group = factor(group,
labels = c('Female', 'Male')),
initial,
final,
change)
#head(df)
#' plot, with regression lines and data ellipses
ggplot(df, aes(x = initial, y = final, color = group)) +
geom_point() +
geom_smooth(method = "lm", formula = y~x) +
stat_ellipse(size = 1.2) +
geom_abline(slope = 1, color = "black", size = 1.2) +
coord_fixed(xlim = c(-.6, 1.2), ylim = c(-.6, 1.2)) +
theme_bw() +
theme(legend.position = c(.15, .85))
This gives the following graph:
In geometry, the coordinates of the -45 degree rotated axes of distributions I want to portray are
(y-x), (x+y) in the original space of the plot. But how can I draw these with
ggplot2 or other software?
An accepted solution can be vague about how the distribution of (y-x) is represented,
but should solve the problem of how to display this on a (y-x) axis.
Fun question! I haven't encountered it yet, but there might be a package to help do this automatically. Here's a manual approach using two hacks:
the clip = "off" parameter of the coord_* functions, to allow us to add annotations outside the plot area.
building a density plot, extracting its coordinates, and then rotating and translating those.
First, we can make a density plot of the change from initial to final, seeing a left skewed distribution:
(my_hist <- df %>%
mutate(gain = final - initial) %>% # gain would be better name
ggplot(aes(gain)) +
geom_density())
Now we can extract the guts of that plot, and transform the coordinates to where we want them to appear in the combined plot:
a <- ggplot_build(my_hist)
rot = pi * 3/4
diag_hist <- tibble(
x = a[["data"]][[1]][["x"]],
y = a[["data"]][[1]][["y"]]
) %>%
# squish
mutate(y = y*0.2) %>%
# rotate 135 deg CCW
mutate(xy = x*cos(rot) - y*sin(rot),
dens = x*sin(rot) + y*cos(rot)) %>%
# slide
mutate(xy = xy - 0.7, # magic number based on plot range below
dens = dens - 0.7)
And here's a combination with the original plot:
ggplot(df, aes(x = initial, y = final, color = group)) +
geom_point() +
geom_smooth(method = "lm", formula = y~x) +
stat_ellipse(size = 1.2) +
geom_abline(slope = 1, color = "black", size = 1.2) +
coord_fixed(clip = "off",
xlim = c(-0.7,1.6),
ylim = c(-0.7,1.6),
expand = expansion(0)) +
annotate("segment", x = -1.4, xend = 0, y = 0, yend = -1.4) +
annotate("path", x = diag_hist$xy, y = diag_hist$dens) +
theme_bw() +
theme(legend.position = c(.15, .85),
plot.margin = unit(c(.1,.1,2,2), "cm"))

ggplot make default point size larger when size is already determined by another variable

I am trying to display data that includes non-detects. For the ND I want to have a circular outline at different sizes so that the lines do not overlap each other. I pretty much have what I want, but for the parameter cis-DCE the circular outline just makes the point look bigger instead of being a distinct outline. How do I attribute size to the parameter and also make the starting size larger?
I will include all of the code I am using for the graphing, but I am specifically working on this bit right now.
geom_point(aes(x= date, y = lrl, group = parm_nmShort, size = parm_nmShort), shape = 1) + #marking lower limit
I also know that I could use facet_wraps and I've done that previously, but historically this data has been shown in one graph, but without identifying the NDs and I do not want to drastically alter the display of the data and confuse anyone.
{
#graphing
# folder where you want the graphs to be saved:
results <- 'C:/Users/cbuckley/OneDrive - DOI/Documents/Projects/New Haven/Data/Graphs/'
{
VOC.graph <- function(df, na.rm = TRUE, ...){
df$parm_nmShort <- factor(df$parm_nm, levels = c("cis.1.2.Dichloroethene_77093",
"Trichloroethene_34485",
"Tetrachloroethene_34475"),
labels = c("cis-DCE", "TCE", "PCE"))
# create list of sites in data to loop over
site_list <- unique(df$site_nm)
# create for loop to produce ggplot2 graphs
for (i in seq_along(site_list)) {
# create plot for each county in df
plot <-
ggplot(subset(df, df$site_nm==site_list[i]),
aes(x = date, y = result,
group = parm_nmShort,
color = parm_nmShort)) +
geom_point() + #add data point plot
geom_line() + #add line plot
#geom_point(aes(y = lrl, group = parm_nmShort, shape = parm_nmShort)) +
geom_point(aes(x= date, y = lrl, group = parm_nmShort, size = parm_nmShort), shape = 1) + #marking lower limit
#scale_shape_manual(values = c("23","24","25")) + #create outlier shapes
#facet_wrap(~parm_nmShort) +
ggtitle(site_list[i]) + #name graphs well names
# theme(legend.position="none") + #removed legend
labs(x = "Year", y = expression(paste("Value, ug/L"))) + #add x and y label titles
theme_article() + #remove grey boxes, outline graph in black
theme(legend.title = element_blank()) + #removes legend title
scale_x_date(labels = date_format("%y"),
limits = as.Date(c("2000-01-01","2021-01-01"))) #+ # set x axis for all graphs
# geom_hline(yintercept = 5) #+ #add 5ug/L contaminant limit horizontal line
# theme(axis.text.x = element_text(angle = 45, size = 12, vjust = 1)) + #angles x axis titles 45 deg
# theme(aspect.ratio = 1) +
# scale_color_hue(labels = c("cic-DCE", "PCE", "TCE")) + #change label names
# scale_fill_discrete(breaks = c("PCE", "TCE", "cic-DCE"))
# Code below will let you block out below the resolution limit
# geom_ribbon(aes(ymin = 0, ymax = ###LRL###), fill ="white", color ="grey3") +
# geom_line(color ="black", lwd = 1)
#ggsave(plot,
# file=paste(results, "", site_list[i], ".png", sep=''),
# scale=1)
# print plots to screen
print(plot)
}
}
#run graphing function with long data set
VOC.graph(data)
}}
Well after a lot of playing around, I figured out the answer to my own question. I figured I'd leave the question up because none of the solutions I found online worked for me but this code did.
geom_point(aes(x= date, y = lrl, group = parm_nmShort, shape = parm_nmShort, size = parm_nmShort)) + #identify non detects
scale_shape_manual(values = c(1,1,1)) +
scale_size_manual(values = c(3,5,7)) +
I'm not very good at R, but for some reason when I didn't include the group and shape in the aes as parm_nmShort, I couldn't mannualy change the values. I don't know if it's because I have more than one geom_point in my whole script and so maybe it didn't know which one to change.

How to include number of observations in each quartile of boxplot using ggplot2 in R?

I am plotting a box-plot to see the distribution of the variable. I am also interested in seeing the number of observations in each quartile. Is there any way to add the number of observations in each quartile to the boxplot along with the values of quartiles?
I included some code below which can generate box-plot with the values of quartiles.
df <- datasets::iris
boxplot <- ggplot(df, aes(x = "", y = Sepal.Length)) +
geom_boxplot(width=0.1, position = "dodge", fill = "red") +
stat_boxplot(geom = "errorbar", width = 0.1) +
stat_summary(geom = "label_repel", fun.y = quantile, aes(label = ..y..),
position = position_nudge(x = -0.1), size = 3) +
ggtitle("") +
xlab("") +
ylab('Sepal.Length')
I expect the values of quartiles on the left-hand side of the plot and the number of observations on the right-hand side of the plot if possible.
this would be one possibility. I always prefer to have my additional data as an extra data frame, because this gives me more control on what is how calculated.
Counting made with some inspiration from https://stackoverflow.com/a/54451575
quantile_counts=function(x){
df= data.frame(label=table(cut(x, quantile(x))),
label_pos=diff(quantile(x))/2+quantile(x)[1:4])
return(df)
}
df_quantile_counts=quantile_counts(df$Sepal.Length)
boxplot <- ggplot(df, aes(x = "", y = Sepal.Length)) +
geom_boxplot(width=0.1, position = "dodge", fill = "red") +
stat_boxplot(geom = "errorbar", width = 0.1) +
stat_summary(geom = "label", fun.y = quantile, aes(label = ..y..),
position = position_nudge(x = -0.1), size = 3) +
geom_text(data=df_quantile_counts,aes(x="",y=label_pos,label = label.Freq),
position = position_nudge(x = +0.1), size = 3) +
ggtitle("") +
xlab("") +
ylab('Sepal.Length')
HTH, Tobi
#TobiO 's answer is correct. But, my data was kind of skewed and some cut points were the same (such as the first and second cut points were the same). I needed to take the unique values to calculate the number of observations in each quartile. Another point is related to usage of cut function which does not include the starting point (low bound, high bound]. In order to include the starting point, I have used the cut2 function from the Hmisc package. I included a label_pos_extension line in order to prevent the overlap of label/text for the quartiles whose cut points are very close to each other. geom_text_repel did not work for preventing the overlaps.
quantile_counts2 <- function(x){
label_pos_extension <- c(0,3,4,0)
if(length(unique(quantile(x))) < 5){
df <- data.frame(label = table(cut2(x, g = 4)),
label_pos = c(0, diff(unique(quantile(x))) / 2 + quantile(x)[1:length(unique(quantile(x)))-1]) + label_pos_extension[1:length(unique(quantile(x)))])
} else {
df <- data.frame(label = table(cut2(x, g = 4)),
label_pos = diff(quantile(x)) / 2 + quantile(x)[1:4] + label_pos_extension)
} return(df)
}
PS. I tried to put my edited function in comment but, it did not work.

Plotting overlapping positions in R

I have a dataframe in R like this:
dat = data.frame(Sample = c(1,1,2,2,3), Start = c(100,300,150,200,160), Stop = c(180,320,190,220,170))
And I would like to plot it such that the x-axis is the position and the y-axis is the number of samples at that position, with each sample in a different colour. So in the above example you would have some positions with height 1, some with height 2 and one area with height 3. The aim being to find regions where there are a large number of samples and what samples are in that region.
i.e. something like:
&
---
********- -- **
where * = Sample 1, - = Sample 2 and & = Sample 3
My first try:
dat$Sample = factor(dat$Sample)
ggplot(aes(x = Start, y = Sample, xend = Stop, yend = Sample, color = Sample), data = dat) +
geom_segment(size = 2) +
geom_segment(aes(x = Start, y = 0, xend = Stop, yend = 0), size = 2, alpha = 0.2, color = "black")
I combine two segment geometries here. One draws the colored vertical bars. These show where Samples have been measured. The second geometry draws the grey bar below where the density of the samples is shown. Any comments to improve on this quick hack?
This hack may be what you're looking for, however I've greatly increased the size of the dataframe in order to take advantage of stacking by geom_histogram.
library(ggplot2)
dat = data.frame(Sample = c(1,1,2,2,3),
Start = c(100,300,150,200,160),
Stop = c(180,320,190,220,170))
# Reformat the data for plotting with geom_histogram.
dat2 = matrix(ncol=2, nrow=0, dimnames=list(NULL, c("Sample", "Position")))
for (i in seq(nrow(dat))) {
Position = seq(dat[i, "Start"], dat[i, "Stop"])
Sample = rep(dat[i, "Sample"], length(Position))
dat2 = rbind(dat2, cbind(Sample, Position))
}
dat2 = as.data.frame(dat2)
dat2$Sample = factor(dat2$Sample)
plot_1 = ggplot(dat2, aes(x=Position, fill=Sample)) +
theme_bw() +
opts(panel.grid.minor=theme_blank(), panel.grid.major=theme_blank()) +
geom_hline(yintercept=seq(0, 20), colour="grey80", size=0.15) +
geom_hline(yintercept=3, linetype=2) +
geom_histogram(binwidth=1) +
ylim(c(0, 20)) +
ylab("Count") +
opts(axis.title.x=theme_text(size=11, vjust=0.5)) +
opts(axis.title.y=theme_text(size=11, angle=90)) +
opts(title="Segment Plot")
png("plot_1.png", height=200, width=650)
print(plot_1)
dev.off()
Note that the way I've reformatted the dataframe is a bit ugly, and will not scale well (e.g. if you have millions of segments and/or large start and stop positions).

Resources