I am trying to plot two Cumulative Frequency curves in ggplot, and shade the cross over at a certain cut off. I haven't been using ggplot for long, so I was hoping someone might be able to help me with this one.
The plot without filled regions, looks like this...
Which I have created using the following code...
library(ggplot2) # required
north <- rnorm(3060, mean=277,sd=3.01) # to create synthetic data
south <- rnorm(3060, mean=278, sd=3.26) # in place of my real data.
#placing in dataframe
df_temp <- data.frame(temp=c(north,south),
region=c(rep("north",length=3060),rep("south",length=3060)))
#manipulating into cdf, as I've seen in other examples
temp.regions <- ddply(df_temp, .(region), summarize,
temp = unique(temp),
ecdf = ecdf(temp)(unique(temp)))
# feeding into ggplot.
ggplot(temp.regions,aes(x=temp, y=ecdf, color = region)) +
geom_line(aes(x=temp,color=region))+
scale_colour_manual(values = c("blue","red"))
What I would then like, would be to shade both curves for temperatures below 0.2 on the y axis. Ideally I'd like to see the blue one shaded in blue, and the red one shaded in red. Then, where they cross over in purple.
However, the closest I have managed is as follows... ]
Which I have achieved using the following additions to my code.
# creating a dataframe with just the temperatures for below 0.2
# to try and aid control when plotting
temp.below <- temp.regions[which(temp.regions$ecdf<0.2),]
# plotting routine again.
ggplot(temp.regions, aes(x=temp, y=ecdf, color = region)) +
geom_line(aes(x=temp,color=region))+
scale_colour_manual(values = c("blue","red"))+
# with additional line for shading.
geom_ribbon(data=temp.below,
aes(x=temp,ymin=0,ymax=0.2), alpha=0.5)
I've seen a few examples of people shading for a normal distribution density plot, which is where I have adapted my code from. But for some reason my boxes don't seem to want anything to do with the temperature curve.
Please help! I'm sure it's quite simple, I'm just really lost and have tried a few, producing less convincing results than these.
Thank you so much for taking a look.
PROBLEM SOLVED THANKS TO HELP BELOW...
running suggested code from below
geom_ribbon(aes(ymin=0,ymax=ecdf, fill=region), alpha=0.5)
gives...
which is so very almost the solution I'm after, but with one final addition... like so
#geom_ribbon(aes(ymin=0,ymax=ecdf, fill=region), alpha=0.5)
geom_ribbon(data=temp.below, aes(ymin=0,ymax=ecdf, fill=region), alpha=0.5)
I get what I'm after...
The reason I set the data again is so that it only fills the lowest 20% of the two regions.
Thank you so much for the help :-)
Looks like you're thinking about it in the right way.
With geom_ribbon i dont think you need to set data to anything else. Just set aes(ymin = 0, ymax = ecdf, fill = region). I think that should do it.
Related
I'm hoping to get some help on making the following histogram looks as nice and understandable as possible. I am plotting the salaries of Immigrant versus US Born workers. I am wondering
1. How would you modify colors, axis intervals, etc. to make the graph more clear/appealing?
2. How could I add a key to indicate purple is for US born workers, and pink is for foreign born?
3. How can I add two different lines to indicate the median of each group? And a corresponding label for each?
My current code is set up as this:
ggplot(NHIS1,aes(x=adj_SALARY, y=..density..)) +
geom_histogram(data=subset(NHIS1,IMMIGRANT=='0'), alpha=.5,binwidth=800, fill="purple",position="identity") + xlim(4430.4,50000) +
geom_vline(xintercept=median(NHIS1$adj_SALARY), col="black", linetype="dashed") +
geom_histogram(data=subset(NHIS1,IMMIGRANT=='1'), alpha=.5,binwidth=800,fill="red") + xlim(4430.4,50000)
geom_vline(xintercept=median(NHIS1$adj_SALARY), col="black", linetype="dashed")
And my final histogram at the moment appears as this:
If you have two variables, one for income , one for immigrant status, you do not need to plot two histograms but one will suffice if you specify the grouping. Also, I'd suggest you also use density lines, which help smooth over the histogram's bumps:
Assuming this is roughly like your data:
df <- data.frame(income = sample(1000:5000, 1000),
born = sample(c("US", "Foreign"), 1000, replace = T))
Then a crude way to plot one histogram as well as density lines for the two groups would be this:
ggplot(df, aes(x=income, color=born, fill=born)) +
geom_histogram(aes(y=..density..), alpha=0.5, binwidth=100,
position="identity") +
geom_density(alpha=.2)
This question has been asked before: overlaying-histograms-with-ggplot2-in-r discusses several options with many examples. You should definitely take a look at it.
Another option to compare the distributions could be violin plots using geom_violin(). I see violin plots as the better option when you need to compare distributions because they give you more flexibility and are still clearer. But that may be just me. Refer to the examples in the manual.
I have a dataset myData which contains x and y values for various Samples. I can create a line plot for a dataset which contains a few Samples with the following pseudocode, and it is a good way to represent this data:
myData <- data.frame(x = 290:450, X52241 = c(..., ..., ...), X75123 = c(..., ..., ...))
myData <- myData %>% gather(Sample, y, -x)
ggplot(myData, aes(x, y)) + geom_line(aes(color=Sample))
Which generates:
This turns into a Spaghetti Plot when I have a lot more Samples added, which makes the information hard to understand, so I want to represent the "hills" of each sample in another way. Preferably, I would like to represent the data as a series of stacked bars, one for each myData$Sample, with transparency inversely related to what is in myData$y. I've tried to represent that data in photoshop (badly) here:
Is there a way to do this? Creating faceted plots using facet_wrap() or facet_grid() doesn't give me what I want (far too many Samples). I would also be open to stacked ridgeline plots using ggridges, but I am not understanding how I would be able to convert absolute values to a stat(density) value needed to plot those.
Any suggestions?
Thanks to u/Joris for the helpful suggestion! Since, I did not find this question elsewhere, I'll go ahead and post the pretty simple solution to my question here for others to find.
Basically, I needed to apply the alpha aesthetic via aes(alpha=y, ...). In theory, I could apply this over any geom. I tried geom_col(), which worked, but the best solution was to use geom_segment(), since all my "bars" were going to be the same length. Also note that I had to "slice" up the segments in order to avoid the problem of overplotting similar to those found here, here, and here.
ggplot(myData, aes(x, Sample)) +
geom_segment(aes(x=x, xend=x-1, y=Sample, yend=Sample, alpha=y), color='blue3', size=14)
That gives us the nice gradient:
Since the max y values are not the same for both lines, if I wanted to "match" the intensity I normalized the data (myDataNorm) and could make the same plot. In my particular case, I kind of preferred bars that did not have a gradient, but which showed a hard edge for the maximum values of y. Here was one solution:
ggplot(myDataNorm, aes(x, Sample)) +
geom_segment(aes(x=x, xend=x-1, y=Sample, y=end=Sample, alpha=ifelse(y>0.9,1,0)) +
theme(legend.position='none')
Better, but I did not like the faint-colored areas that were left. The final code is what gave me something that perfectly captured what I was looking for. I simply moved the ifelse() statement to apply to the x aesthetic, so the parts of the segment drawn were only those with high enough y values. Note my data "starts" at x=290 here. Probably more elegant ways to combine those x and xend terms, but whatever:
ggplot(myDataNorm, aes(x, Sample)) +
geom_segment(aes(
x=ifelse(y>0.9,x,290), xend=ifelse(y>0.9,x-1,290),
y=Sample, yend=Sample), color='blue3', size=14) +
xlim(290,400) # needed to show entire scale
I have a dataframe that I want to reorder to make a ggplot so I can easily see which items have the highest and lowest values in them. In my case, I've grouped the data into two groups, and it'd be nice to have a visual representation of which group tends to score higher. Based on this question I came up with:
library(ggplot2)
cor.data<- read.csv("https://dl.dropbox.com/s/p4uy6uf1vhe8yzs/cor.data.csv?dl=0",stringsAsFactors = F)
cor.data.sorted = cor.data[with(cor.data,order(r.val,pic)),] #<-- line that doesn't seem to be working
ggplot(cor.data.sorted,aes(x=pic,y=r.val,size=df.val,color=exp)) + geom_point()
which produces this:
I've tried quite a few variants to reorder the data, and I feel like this should be pretty simple to achieve. To clarify, if I had succesfully reorganised the data then the y-values would go up as the plot moves along the x-value. So maybe i'm focussing on the wrong part of the code to achieve this in a ggplot figure?
You could do something like this?
library(tidyverse);
cor.data %>%
mutate(pic = factor(pic, levels = as.character(pic)[order(r.val)])) %>%
ggplot(aes(x = pic, y = r.val, size = df.val, color = exp)) + geom_point()
This obviously still needs some polishing to deal with the x axis label clutter etc.
Rather than try to order the data before creating the plot, I can reorder the data at the time of writing the plot:
cor.data<- read.csv("https://dl.dropbox.com/s/p4uy6uf1vhe8yzs/cor.data.csv?dl=0",stringsAsFactors = F)
cor.data.sorted = cor.data[with(cor.data,order(r.val,pic)),] #<-- This line controls order points drawn created to make (slightly) more readible plot
gplot(cor.data.sorted,aes(x=reorder(pic,r.val),y=r.val,size=df.val,color=exp)) + geom_point()
to create
I've been searching for a while, and I've found a number of answers for problems similar to mine, but not quite working when I try to implement them.
I'm trying to make a series of radar plots for different observations of performance. The data has been normalized such that the mean is 0 and the standard deviation is 1, and the y-axis on the plot has been set from -3 to 3 so as to make it visually comparable how well the subjects performed, with more extreme observations being worse. I would like to add colors associated with that scale, preferably such that -1 to 1 is green, and then the bands between +/- 1-2 is yellow and +/- 2-3 is red. All the examples I've been able to find relating to color fills is based directly in the data or from factors rather than a fixed scale, and anything I try seems to not show correctly. I'm not even sure if it is normally in the functionality of ggplot to be able to set a color scale in the way I'm looking for...
Here's the toy data I've been working with while working out the plotting (after reshaping):
variable <- c("time", "distance", "turns")
value <- c(0.9536197, 0.5842319, -2.1814528)
df <- data.frame(variable, value)
and here's my most recent attempt as far as ggplot code goes (using ggiraphExtra):
ggplot(temp, aes(x=variable, y=value, group=1)) + geom_point() + geom_polygon() +
ggiraphExtra:::coord_radar() + ylim(-3,3) +
scale_fill_gradient(low="red", high="green")
and this is the output:
radar plot with solid green geom_polygon fill
I have a more general question regarding the principle behind density2d.
I'm using ggplot and the density2d function to visualize animal movements. My idea was calculating heat maps showing where the animal is most of the time and/or to identify areas of particular interest. Yet, the density2d function sometimes generates rather inexplicable plots.
Here's what I mean:
set.seed(4)
x<-runif(50,1,599)
y<-runif(50,1,599)
df<-data.table(x,y)
ggplot(df,aes(x=x,y=y))
+stat_density2d(aes(x=x,y=y,fill=..level..,alpha=..level..),bins=50,geom="polygon")
+coord_equal(xlim=c(0,600),ylim=c(0,600))
+expand_limits(x=c(0,600),y=c(0,600))
+geom_path()
which looks like this:
There are areas with a density estimate but without data (around x:50, y:300).
Now compare with this:
set.seed(13)
x<-runif(50,1,599)
y<-runif(50,1,599)
df<-data.table(x,y)
ggplot(df,aes(x=x,y=y))
+stat_density2d(aes(x=x,y=y,fill=..level..,alpha=..level..),bins=50,geom="polygon")
+coord_equal(xlim=c(0,600),ylim=c(0,600))
+expand_limits(x=c(0,600),y=c(0,600))
+geom_path()
which looks like this:
Here there are regions "wihtout" a density estimate but with actual data (around x:100,y:550).
Someone asked a related question:
Create heatmap with distribution of attribute values in R (not density heatmap)
but there are no satisfactory answers to be found.
So my question would be (i) Why? and (ii) How to avoid/adjust if possible?
This may be helpful. I am not that familiar with stat_density2d. After seeing your code and ggplot documents (http://docs.ggplot2.org/0.9.2.1/stat_density2d.html), I thought ..level.. might not be the one. I, then, tried ..density.. Someone will be able to explain why you need density meanwhile I think this is the graph you wanted.
ggplot(data = df, aes(x = x, y = y)) +
stat_density2d(geom="tile", aes(fill = ..density..), contour = FALSE) +
geom_path() +
coord_equal(xlim=c(0,600),ylim=c(0,600)) +
expand_limits(x=c(0,600),y=c(0,600))