How to modify ggplot2 legend_text? - r

I use
geom_point(aes(colour = factor(ClusterID)))
but I want to get ClusterID visible without the word factor.
How can I modify the legend title in ggplot2?

Better to do the factor conversion before plotting. For example using dplyr, assuming data frame mydata and variables x, y:
library(dplyr)
mydata %>%
mutate(ClusterID = factor(ClusterID)) %>%
ggplot(aes(x, y)) + geom_point(aes(color = ClusterID))
Another option is to name the legend in scale_color_discrete:
ggplot(mydata, aes(x, y)) +
geom_point(aes(color = factor(ClusterID))) +
scale_color_discrete(name = "ClusterID")

Related

How can you plot `geom_point()` with `facet_wrap()` using per-group row number as x?

Is there a way to plot geom_point() so that it implicitly uses the row number as x in a facet? Just like plot(y) but also for multiple facets.
The following fails with Error: geom_point requires the following missing aesthetics: x:
df = data.frame(y = rnorm(60), group = rep(c("A", "B", "C"), 20))
ggplot(df, aes(y = y)) +
geom_point() +
facet_wrap(~group)
Naturally, you can do it using something like the following, but it is quite cumbersome.
df = df %>%
group_by(group) %>%
mutate(row = row_number())
ggplot(df, aes(x = row, y = y)) +
geom_point() +
facet_wrap(~group)
You can try this:
ggplot(df, aes(x=seq(y),y = y))+geom_point() + facet_wrap(~group)
In that way you can avoid the creation of an index variable as you mentioned!!!

Prevent reordering within facet_wrap()

I have an issue with my ggplot() reordering the data. I have an example code below. I have data, and reordered the factors in feed to my content, but after the str_extract() in facet_wrap(), the data gets reordered back before I reordered it. Is there a way to prevent that from occurring? For my actual code, it is important for me to use regex within the facet_wrap() in ggplot,
data <- chickwts
data <- mutate(data, time = 1:nrow(data))
lvl <- c("linseed", "meatmeal", "sunflower", "soybean",
"casein", "horsebean")
data$feed <- factor(data$feed, levels = lvl)
ggplot(data, aes(x = time, y = weight, color = feed)) +
geom_line(size = 1) + geom_point(size = 1.75) +
facet_wrap(~str_extract(feed,"[a-z]+"))
You could put the factor inside the facet_wrap:
ggplot(data, aes(x = time, y = weight, color = feed)) +
geom_line(size = 1) + geom_point(size = 1.75) +
facet_wrap(~ factor(str_extract(feed,"[a-z]+"), levels = lvl))

Display Greek symbols and charge facet titles at the same time with ggplot

I know how to modify titles in ggplot without altering the original data. Suppose I have the following data frame and I want to change the labels. Then, I would do so in the following way
df <- data.frame(x = 1:4, y = 1:4, label = c(c("params[1]", "params[2]", "params[3]",
"params[4]")))
params_names <- list(
'params[1]'= "beta[11]",
'params[2]'= "beta[22]",
'params[3]'= "beta[33]",
'params[4]'= "beta[44]"
)
param_labeller <- function(variable, value){
params_names[value]
}
ggplot(df, aes(x=x,y=y)) +
geom_point() +
facet_grid(~label, labeller = param_labeller)
If I wanted to display the subscripts, I would just do this
ggplot(df, aes(x=x,y=y)) +
geom_point() +
facet_grid(~label, labeller = label_parsed)
How do I apply both operations at the same time?
I don't know exactly if this conflicts with you not wanting to "alter" the original data, but you add the labelling information to the factor itself:
df$label2 <- factor(df$label,
labels = c("beta[4]", "beta[24]", "beta[42]", "beta[43]"))
ggplot(df, aes(x = x, y = y)) +
geom_point() +
facet_grid( ~ label2, labeller = label_parsed)
This produces the following plot:
Plot with formatted facet labels

How to create a heatmap with continuous scale using ggplot2 in R

I have got a data frame with several 1000 rows in the form of
group = c("gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3")
pos = c(1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10)
color = c(2,2,2,2,3,3,2,2,3,2,1,2,2,2,1,1,1,1,1,1,2,2,2,2,2,2,1,1,2,2)
df = data.frame(group, pos, color)
and would like to make a kind of heatmap in which one axes has a continuous scale (position). The color column is categorical. However due to the large amount of data points I want to use binning, i.e. use it as a continuous variable.
This is more or less how the plot should look like:
I can't think of a way to create such a plot using ggplot2/R. I have tried several geometries, e.g. geom_point()
ggplot(data=df, aes(x=strain, y=pos, color=color)) +
geom_point() +
scale_colour_gradientn(colors=c("yellow", "black", "orange"))
Thanks for your help in advance.
Does this help you?
library(ggplot2)
group = c("gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr1","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr2","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3","gr3")
pos = c(1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10)
color = c(2,2,2,2,3,3,2,2,3,2,1,2,2,2,1,1,1,1,1,1,2,2,2,2,2,2,1,1,2,2)
df = data.frame(group, pos, color)
ggplot(data = df, aes(x = group, y = pos)) + geom_tile(aes(fill = color))
Looks like this
Improved version with 3 color gradient if you like
library(scales)
ggplot(data = df, aes(x = group, y = pos)) + geom_tile(aes(fill = color))+ scale_fill_gradientn(colours=c("orange","black","yellow"),values=rescale(c(1, 2, 3)),guide="colorbar")

Plot discrete values with different color

Given a dataframe with discrete values,
d=data.frame(id=1:6, a=c(1,1,1,0,0,0), b=c(0,0,0,1,1,1), c=c(10,20,30,30,10,20))
I want to make a plot like
However I want to make different color for each layer, say red and green for "a", yellow/blue for "b".
The idea is to reshape your data (define coordinates to draw the rectangles) in order to use geom_rect from ggplot:
library(ggplot2)
library(reshape2)
i = setNames(expand.grid(1:nrow(d),1:ncol(d[-1])),c('x1','y1'))
ggplot(cbind(i,melt(d, id.vars='id')),
aes(xmin=x1, xmax=x1+1, ymin=y1, ymax=y1+1, color=variable, fill=value)) +
geom_rect()
Try geom_tile(). But you need to reshape your data to get exactly the same figure as you presented.
df <- data.frame(id=factor(c(1:6)), a=c(1,1,1,0,0,0), b=c(0,0,0,1,1,1), c=c(10,20,30,30,10,20))
library(reshape2)
df <- melt(df, vars.id = c(df$id))
library(ggplot2)
ggplot(aes(x = id, y = variable, fill = value), data = df) + geom_tile()
require("dplyr")
require("tidyr")
require("ggplot2")
d=data.frame(id=1:6, a=c(1,1,1,0,0,0), b=c(0,0,0,1,1,1), c=c(10,20,30,30,10,20))
ggplot(d %>% gather(type, value, a, b, c) %>% mutate(value = paste0(type, value)),
aes(x = id, y = type)) +
geom_tile(aes(fill = value), color = "white") +
scale_fill_manual(values = c("forestgreen", "indianred", "lightgoldenrod1",
"royalblue", "plum1", "plum2", "plum3"))
First we use reshape2 to transform the data from wide to long. Then to get discrete values we use as.factor(value) and finally we use scale_fill_manual to assign the 5 different colours we need. In geom_tile we specify the colour of the tile borders.
library(reshape2)
library(ggplot2)
df <- data.frame(id=1:6, a=c(1,1,1,0,0,0), b=c(0,0,0,1,1,1), c=c(10,20,30,30,10,20))
df <- melt(df, id.vars=c("id"))
ggplot(df, aes(id, variable, fill = as.factor(value))) + geom_tile(colour = "white") +
scale_fill_manual(values = c("lightblue", "steelblue2", "steelblue3", "steelblue4", "darkblue"), name = "Values")+
scale_x_discrete(limits = 1:6)

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