Manually added legend not working in ggplot2? - r

Here's facsimile of my data:
d1 <- data.frame(
e=rnorm(3000,10,10)
)
d2 <- data.frame(
e=rnorm(2000,30,30)
)
So, I got around the problem of plotting two different density distributions from two very different datasets on the same graph by doing this:
ggplot() +
geom_density(aes(x=e),fill="red",data=d1) +
geom_density(aes(x=e),fill="blue",data=d2)
But when I try to manually add a legend, like so:
ggplot() +
geom_density(aes(x=e),fill="red",data=d1) +
geom_density(aes(x=e),fill="blue",data=d2) +
scale_fill_manual(name="Data", values = c("XXXXX" = "red","YYYYY" = "blue"))
Nothing happens. Does anybody know what's going wrong? I thought I could actually manually add legends if need be.

Generally ggplot works best when your data is in a single data.frame and in long format. In your case we therefore want to combine the data from both data.frames. For this simple example, we just concatenate the data into a long variable called d and use an additional column id to indicate to which dataset that value belongs.
d.f <- data.frame(id = rep(c("XXXXX", "YYYYY"), c(3000, 2000)),
d = c(d1$e, d2$e))
More complex data manipulations can be done using packages such as reshape2 and tidyr. I find this cheat sheet often useful. Then when we plot we map fill to id, and ggplot will take of the legend automatically.
ggplot(d.f, aes(x = d, fill = id)) +
geom_density()

Related

How to incorporate data into plot which was constructed in ggplot2 using data from another file (R)?

Using a dataset, I have created the following plot:
I'm trying to create the following plot:
Specifically, I am trying to incorporate Twitter names over the first image. To do this, I have a dataset with each name in and a value that corresponds to a point on the axes. A snippet looks something like:
Name Score
#tedcruz 0.108
#RealBenCarson 0.119
Does anyone know how I can plot this data (from one CSV file) over my original graph (which is constructed from data in a different CSV file)? The reason that I am confused is because in ggplot2, you specify the data you want to use at the start, so I am not sure how to incorporate other data.
Thank you.
The question you ask about ggplot combining source of data to plot different element is answered in this post here
Now, I don't know for sure how this is going to apply to your specific data. Here I want to show you an example that might help you to go forward.
Imagine we have two data.frames (see bellow) and we want to obtain a plot similar to the one you presented.
data1 <- data.frame(list(
x=seq(-4, 4, 0.1),
y=dnorm(x = seq(-4, 4, 0.1))))
data2 <- data.frame(list(
"name"=c("name1", "name2"),
"Score" = c(-1, 1)))
The first step is to find the "y" coordinates of the names in the second data.frame (data2). To do this I added a y column to data2. y is defined here as a range of points from the may value of y to the min value of y with some space for aesthetics.
range_y = max(data1$y) - min(data1$y)
space_y = range_y * 0.05
data2$y <- seq(from = max(data1$y)-space, to = min(data1$y)+space, length.out = nrow(data2))
Then we can use ggplot() to plot data1 and data2 following some plot designs. For the current example I did this:
library(ggplot2)
p <- ggplot(data=data1, aes(x=x, y=y)) +
geom_point() + # for the data1 just plot the points
geom_pointrange(data=data2, aes(x=Score, y=y, xmin=Score-0.5, xmax=Score+0.5)) +
geom_text(data = data2, aes(x = Score, y = y+(range_y*0.05), label=name))
p
which gave this following plot:

Plot multiple traces in R

I started learning R for data analysis and, most importantly, for data visualisation.
Since I am still in the switching process, I am trying to reproduce the activities I was doing with Graphpad Prism or Origin Pro in R. In most of the cases everything was smooth, but I could not find a smart solution for plotting multiple y columns in a single graph.
What I usually get from the softwares I use for data visualisations look like this:
Each single black trace is a measurement, and I would like to obtain the same plot in R. In Prism or Origin, this will take a single copy-paste in a XY graph.
I exported the matrix of data (one X, which indicates the time, and multiple Y values, which are the traces you see in the image).
I imported my data in R with the following commands:
library(ggplot2) #loaded ggplot2
Data <- read.csv("Directory/File.txt", header=F, sep="") #imported data
DF <- data.frame(Data) #transformed data into data frame
If I plot my data now, I obtain a series of columns, where the first one (called V1) is the X axis and all the others (V2 to V140) are the traces I want to put on the same graph.
To plot the data, I tried different solutions:
ggplot(data=DF, aes(x=DF$V1, y=DF[V2:V140]))+geom_line()+theme_bw() #did not work
plot(DF, xy.coords(x=DF$V1, y=DF$V2:V140)) #gives me an error
plot(DF, xy.coords(x=V1, y=c(V2:V10))) #gives me an error
I tried the matplot, without success, following the EZH guide:
The code I used is the following: matplot(x=DF$V1, type="l", lty = 2:100)
The only solution I found would be to individually plot a command for each single column, but it is a crazy solution. The number of columns varies among my data, and manually enter commands for 140 columns is insane.
What would you suggest?
Thank you in advance.
Here there are also some data attached.Data: single X, multiple Y
I tried using the matplot(). I used a very sample data which has no trend at all. so th eoutput from my code shall look terrible, but my main focus is on the code. Since you have already tried matplot() ,just recheck with below solution if you had done it right!
set.seed(100)
df = matrix(sample(1:685765,50000,replace = T),ncol = 100)
colnames(df)=c("x",paste0("y", 1:99))
dt=as.data.frame(df)
matplot(dt[["x"]], y = dt[,c(paste0("y",1:99))], type = "l")
If you want to plot in base R, you have to make a plot and add lines one at a time, however that isn't hard to do.
we start by making some sample data. Since the data in the link seemed to all be on the same scale, I will assume your data frame only has y values and the x value is stored separately.
plotData <- as.data.frame(matrix(sort(rnorm(500)),ncol = 5))
xval <- sort(sample(200, 100))
Now we can initialize a plot with the first column.
plot(xval, plotData[[1]], type = "l",
ylim = c(min(plotData), max(plotData)))
type = "l" makes a line plot instead of a scatter plot
ylim = c(min(plotData), max(plotData)) makes sure the y-axis will fit all the data.
Now we can add the rest of the values.
apply(plotData[-1], 2, lines, x = xval)
plotData[-1] removes the column we already plotted,
apply function with 2 as the second parameter means we want to execute a function on every column,
lines defines the function we are applying to the columns. lines adds a new line to the current plot.
x = xval passes an extra parameter (x) to the lines function.
if you wat to plot the data using ggplot2, the data should be transformed to long format;
library(ggplot2)
library(reshape2)
dat <- read.delim('AP.txt', header = F)
# plotting only first 9 traces
# my rstudio will crach if I plot the full data;
df <- melt(dat[1:10], id.vars = 'V1')
ggplot(df, aes(x = V1, y = value, color = variable)) + geom_line()
# if you want all traces to be in same colour, you can use
ggplot(df, aes(x = V1, y = value, group = variable)) + geom_line()

Combining two ecdf plots with different

At the moment I`m writing my bachelor thesis and all of my plots are created with ggplot2. Now I need a plot of two ecdfs but my problem is that the two dataframes have different lengths. But by adding values to equalize the length I would change the distribution, therefore my first thought isn't possible. But a ecdf plot with two different dataframes with a different length is forbidden.
daten <- peptidPSMotherExplained[peptidPSMotherExplained$V3!=-1,]
daten <- cbind ( daten , "scoreDistance"= daten$V2-daten$V3 )
daten2 <- peptidPSMotherExplained2[peptidPSMotherExplained2$V3!=-1,]
daten2 <- cbind ( daten2 , "scoreDistance"= daten2$V2-daten2$V3 )
p <- ggplot(daten, aes(x = scoreDistance)) + stat_ecdf()
p <- p + geom_point(aes(x = daten2$lengthDistance))
p
with the normal plot function of R it is possible
plot(ecdf(daten$scoreDistance))
plot(ecdf(daten2$scoreDistance),add=TRUE)
but it looks different to all of my other plots and I dislike this.
Has anybody a solution for me?
Thank you,
Tobias
Example:
df <-data.frame(scoreDifference = rnorm(10,0,12))
df2 <- data.frame(scoreDifference = rnorm(5,-3,9))
plot(ecdf(df$scoreDifference))
plot(ecdf(df2$scoreDifference),add=TRUE)
So how can I achieve this kind of plot in ggplot?
I don't know what geom one should use for such plots, but for combining two datasets you can simply specify the data in a new layer,
ggplot(df, aes(x = scoreDifference)) +
stat_ecdf(geom = "point") +
stat_ecdf(data=df2, geom = "point")
I think, reshaping your data in the right way will probably make ggplot2 work for you:
df <-data.frame(scoreDiff1 = rnorm(10,0,12))
df2 <- data.frame(scoreDiff2 = rnorm(5,-3,9))
library('reshape2')
data <- merge(melt(df),melt(df2),all=TRUE)
Then, with data in the right shape, you can simply go on to plot the stuff with colour (or shape, or whatever you wish) to distinguish the two datasets:
p <- ggplot(daten, aes(x = value, colour = variable)) + stat_ecdf()
Hope this is what you were looking for!?

How can I plot multiple variables side-by-side in a dotplot in R?

I'm still pretty new to R, and have come up against a plotting problem I can't find an answer to.
I've got a data frame that looks like this (though a lot bigger):
df <- data.frame(Treatment= rep(c("A", "B", "C"), each = 6),
LocA=sample(1:100, 18),
LocB=sample(1:100, 18),
LocC=sample(1:100, 18))
And I want dot plots that look like this one produced in Excel. It's exactly the formatting I want: a dotplot for each of the treatments side-by-side for each location, with data for multiple locations together on one graph. (Profuse apologies for not being able to post the image here; posting images requires a 10 reputation.)
It's no problem to make a plot for each location, with the dots color-coded, and so on:
ggplot(data = df, aes(x=Treatment, y=LocA, color = Treatment)) + geom_point()
but I can't figure out how to add locations B and C to the same graph.
Any advice would be much appreciated!
As a couple of people have mentioned, you need to "melt" the data, getting it into a "long" form.
library(reshape2)
df_melted <- melt(df, id.vars=c("Treatment"))
colnames(df_melted)[2] <- "Location"
In ggplot jargon, having different groups like treatment side-by-side is achieved through "dodging". Usually for things like barplots you can just say position="dodge" but geom_point seems to require a bit more manual specification:
ggplot(data=df_melted, aes(x=Location, y=value, color=Treatment)) +
geom_point(position=position_dodge(width=0.3))
You need to reshape the data. Here an example using reshape2
library(reshape2)
dat.m <- melt(dat, id.vars='Treatment')
library(ggplot2)
ggplot(data = dat.m,
aes(x=Treatment, y=value,shape = Treatment,color=Treatment)) +
geom_point()+facet_grid(~variable)
Since you want a dotplot, I propose also a lattice solution. I think it is more suitable in this case.
dotplot(value~Treatment|variable,
groups = Treatment, data=dat.m,
pch=c(25,19),
par.strip.text=list(cex=3),
cex=2)

How to create histogram in R with CSV time data?

I have CSV data of a log for 24 hours that looks like this:
svr01,07:17:14,'u1#user.de','8.3.1.35'
svr03,07:17:21,'u2#sr.de','82.15.1.35'
svr02,07:17:30,'u3#fr.de','2.15.1.35'
svr04,07:17:40,'u2#for.de','2.1.1.35'
I read the data with tbl <- read.csv("logs.csv")
How can I plot this data in a histogram to see the number of hits per hour?
Ideally, I would get 4 bars representing hits per hour per srv01, srv02, srv03, srv04.
Thank you for helping me here!
I don't know if I understood you right, so I will split my answer in two parts. The first part is how to convert your time into a vector you can use for plotting.
a) Converting your data into hours:
#df being the dataframe
df$timestamp <- strptime(df$timestamp, format="%H:%M:%S")
df$hours <- as.numeric(format(df$timestamp, format="%H"))
hist(df$hours)
This gives you a histogram of hits over all servers. If you want to split the histograms this is one way but of course there are numerous others:
b) Making a histogram with ggplot2
#install.packages("ggplot2")
require(ggplot2)
ggplot(data=df) + geom_histogram(aes(x=hours), bin=1) + facet_wrap(~ server)
# or use a color instead
ggplot(data=df) + geom_histogram(aes(x=hours, fill=server), bin=1)
c) You could also use another package:
require(plotrix)
l <- split(df$hours, f=df$server)
multhist(l)
The examples are given below. The third makes comparison easier but ggplot2 simply looks better I think.
EDIT
Here is how thes solutions would look like
first solution:
second solution:
third solution:
An example dataset:
dat = data.frame(server = paste("svr", round(runif(1000, 1, 10)), sep = ""),
time = Sys.time() + sort(round(runif(1000, 1, 36000))))
The trick I use is to create a new variable which only specifies in which hour the hit was recorded:
dat$hr = strftime(dat$time, "%H")
Now we can use some plyr magick:
hits_hour = count(dat, vars = c("server","hr"))
And create the plot:
ggplot(data = hits_hour) + geom_bar(aes(x = hr, y = freq, fill = server), stat="identity", position = "dodge")
Which looks like:
I don't really like this plot, I'd be more in favor of:
ggplot(data = hits_hour) + geom_line(aes(x = as.numeric(hr), y = freq)) + facet_wrap(~ server, nrow = 1)
Which looks like:
Putting all the facets in one row allows easy comparison of the number of hits between the servers. This will look even better when using real data instead of my random data.

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