ggplot remove or replace the 'a' in geom_text legends - r

I trying to remove the little a in front of a legend but without any luck. Other possibility would be to create a legend or legend like text next to the graph but I am running out of ideas. Maybe someone can help me.
I plot on specific positions a red X and I want to point out, that the X marked things are imputed...
df <- data.frame(x=rnorm(10),y=rnorm(10))
ggplot(df, aes(x=x, y=y)) + geom_point() + geom_text(aes(x=0,y=0, color=factor(1)), label='X') +
scale_color_manual(values = 'red', name='imputed',labels='imputed') +
theme(legend.key=element_blank(), legend.title=element_blank())
I think the best result would be to replace the little a by a X. But I could not find any solution for it.

The problem is that you use geom_text to draw the cross.
A simple way to solve it is to use geom_point to plot the cross:
ggplot(df, aes(x=x, y=y)) + geom_point() + geom_point(aes(x=0,y=0, color=factor(1)), shape='X', size=5) +
scale_color_manual(values = 'red',labels='imputed') +
theme(legend.key=element_blank(), legend.title=element_blank())

Related

ggplot2 z order of multiple geoms (background to foreground)

I am trying to plot multiple lines with surrounding area, using ggplot2, with geom_ribbon for the are, and a centerline with geom_line. The values are overlapping, but I'd like each ribbon/line combination to be either bottom or top as a combination.
Here's a reproducible example:
library(ggplot2)
x <- 1:10
y <- c(1+x/100, 2-x, .1*x^2)
data <- data.frame(x=rep(x,3), y=y, lower=y-1, upper=y+1, color=rep(c('green', 'blue', 'yellow'), each=10))
In the example I can get the plot I want by using this code:
ggplot() +
geom_ribbon(data=data[data$color=='green',],aes(x=x, ymin=lower, ymax=upper, fill=paste0('light',color))) +
geom_line(data=data[data$color=='green',],aes(x=x, y=y, col=color)) +
geom_ribbon(data=data[data$color=='blue',],aes(x=x, ymin=lower, ymax=upper, fill=paste0('light',color))) +
geom_line(data=data[data$color=='blue',],aes(x=x, y=y, col=color)) +
geom_ribbon(data=data[data$color=='yellow',],aes(x=x, ymin=lower, ymax=upper, fill=paste0('light',color))) +
geom_line(data=data[data$color=='yellow',],aes(x=x, y=y, col=color)) +
scale_color_identity() +
scale_fill_identity()
But when I keep it simple and us this this code
plot <- ggplot(data=data) +
geom_ribbon(aes(x=x, ymin=lower, ymax=upper, fill=paste0('light',color))) +
geom_line(aes(x=x, y=y, col=color)) +
scale_color_identity() +
scale_fill_identity()
the lines of the background data go over the 'top' ribbons, or if I switch the geom_line and geom_ribbon, my middle-lines are no longer visible.
For this example, the lengthy call works, but in my real data, I have a lot more lines, and I'd like to be able to switch lines from background to foreground dynamically.
Is there any way that I can tell ggplot2 that there is an ordering that has to switch between my different geoms?
P.S. I can't post images yet, sorry if my question seems unclear.
You could save some typing with a loop
ggplot(data=data) +
purrr::map(.x = split(data, f = data$color),
.f = function(d){
list(geom_ribbon(data=d,aes(x=x, ymin=lower, ymax=upper), fill=paste0('light',unique(d$color))),
geom_line(data=d,aes(x=x, y=y), col=unique(d$color)))
})

ggplot2: coloured vertical lines

I'd like to create a ggplot graph with vertical lines of different colors. Here one way to achieve this goal.
mtcars$colors = rep(1:4, nrow(mtcars)/4)
ggplot(mtcars, aes(x=wt, y=mpg)) +
geom_point() +
geom_vline(xintercept=subset(mtcars, colors==1)$wt, color="red") +
geom_vline(xintercept=subset(mtcars, colors==2)$wt, color="blue") +
geom_vline(xintercept=subset(mtcars, colors==3)$wt, color="yellow") +
geom_vline(xintercept=subset(mtcars, colors==4)$wt, color="green")
This solution is not very handy when the variable colors takes 50 different values 1) because it asks the user to write a very long expression (or to construct the ggplot object iteratively) and 2) because it does not produce legends for the colors. Is there a better solution?
Maybe this instead:
+ geom_vline(aes(xintercept = wt,color = factor(colors))) +
scale_color_manual(values = c('red','blue','yellow','green'))

`fill` scale is not shown in the legend

Here is my dummy code:
set.seed(1)
df <- data.frame(xx=sample(10,6),
yy=sample(10,6),
type2=c('a','b','a','a','b','b'),
type3=c('A','C','B','A','B','C')
)
ggplot(data=df, mapping = aes(x=xx, y=yy)) +
geom_point(aes(shape=type3, fill=type2), size=5) +
scale_shape_manual(values=c(24,25,21)) +
scale_fill_manual(values=c('green', 'red'))
Resulting plot has a legend but it's 'type2' section doesn't reflect scale of fill value - is it by design?
I know this is an old thread, but I ran into this exact problem and want to post this here for others like me. While the accepted answer works, the less risky, cleaner method is:
library(ggplot2)
ggplot(data=df, mapping = aes(x=xx, y=yy)) +
geom_point(aes(shape=type3, fill=type2), size=5) +
scale_shape_manual(values=c(24,25,21)) +
scale_fill_manual(values=c(a='green',b='red'))+
guides(fill=guide_legend(override.aes=list(shape=21)))
The key is to change the shape in the legend to one of those that can have a 'fill'.
Here's a different workaround.
library(ggplot2)
ggplot(data=df, mapping = aes(x=xx, y=yy)) +
geom_point(aes(shape=type3, fill=type2), size=5) +
scale_shape_manual(values=c(24,25,21)) +
scale_fill_manual(values=c(a='green',b='red'))+
guides(fill=guide_legend(override.aes=list(colour=c(a="green",b="red"))))
Using guide_legend(...) with override_aes is a way to influence the appearance of the guide (the legend). The hack is that here we are "overriding" the fill colors in the guide with the colors they should have had in the first place.
I played with the data and came up with this idea. I first assigned shape in the first geom_point. Then, I made the shapes empty. In this way, outlines stayed in black colour. Third, I manually assigned specific shape. Finally, I filled in the symbols.
ggplot(data=df, aes(x=xx, y=yy)) +
geom_point(aes(shape = type3), size = 5.1) + # Plot with three types of shape first
scale_shape(solid = FALSE) + # Make the shapes empty
scale_shape_manual(values=c(24,25,21)) + # Assign specific types of shape
geom_point(aes(color = type2, fill = type2, shape = type3), size = 4.5)
I'm not sure if what you want looks like this?
ggplot(df,aes(x=xx,y=yy))+
geom_point(aes(shape=type3,color=type2,fill=type2),size=5)+
scale_shape_manual(values=c(24,25,21))

ggplot2: How to specify multiple fill colors for points that are connected by lines of different colors

I am new to ggplot2. I would like to create a line plot that has points on them where the points are filled with different colors than the lines (see the plot below).
Suppose the dataset I am working with is the one below:
set.seed(100)
data<-data.frame(dv=c(rnorm(30), rnorm(30, mean=1), rnorm(30, mean=2)),
iv=rep(1:30, 3),
group=rep(letters[1:3], each=30))
I tried the following code:
p<-ggplot(data, aes(x=iv, y=dv, group=group, pch=group)) + geom_line() + geom_point()
p + scale_color_manual(values=rep("black",3))+ scale_shape(c(19,20,21)) +
scale_fill_manual(values=c("blue", "red","gray"))
p + scale_shape(c(19,20,21)) + scale_fill_manual(values=c("blue", "red","gray"))
But I do not get what I want.I hope someone can point me to the right direction. Thanks!
scale_fill_manual(), scale_shape_manual() and scale_colour_manual() can be used only if you have set fill=, shape= or colour= inside the aes().
To change colour just for the points you should add colour=group inside geom_point() call.
ggplot(data, aes(x=iv, y=dv, group=group,shape=group)) +
geom_line() + geom_point(aes(colour=group)) +
scale_shape_manual(values=c(19,20,21))+
scale_colour_manual(values=c("blue", "red","gray"))

Seemingly incorrect guide color when geom_line() and geom_segment() are used together

I'm drawing some line segments on top of a plot that uses geom_line(). Surprisingly, the guide (legend) colors for geom_line() are drawn as the color of the last element I add to the plot - even if it is not the geom_line(). This looks like a bug to me, but it could be expected behavior for some reason I don't understand.
#Set up the data
require(ggplot2)
x <- rep(1:10, 2)
y <- c(1:10, 1:10+5)
fac <- gl(2, 10)
df <- data.frame(x=x, y=y, fac=fac)
#Draw the plot with geom_segment second, and the guide is the color of the segment
ggplot(df, aes(x=x, y=y, linetype=fac)) +
geom_line() +
geom_segment(aes(x=2, y=7, xend=7, yend=7), colour="red")
Whereas if I add the geom_segment first, the colors on the guide are black as I would expect:
ggplot(df, aes(x=x, y=y, linetype=fac)) +
geom_segment(aes(x=2, y=7, xend=7, yend=7), colour="red") +
geom_line()
Feature or bug? If the first, can someone explain what's happening?
Feature(ish). The guide that is drawn is a guide for linetype. But, it has to be drawn in some color to be seen. When the color is not specified by an aesthetic mapping, ggplot2 draws it in a color that is consistent with the plot. I'm speculating that the default is whatever last color was used. That is why you are seeing differences when you plot them in a different order.
However, you can control these details of the legend.
ggplot(df, aes(x=x, y=y, linetype=fac)) +
geom_line() +
geom_segment(aes(x=2, y=7, xend=7, yend=7), colour="red") +
scale_linetype_discrete(guide=guide_legend(override.aes=aes(colour="blue")))

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