Adding lines and legends in R - r

I am trying to figure out how to add both points and lines (in color) to a legend in R.
What I want to plot is something like this:
x = 1:10
y = sin(x)
z = cos(x)
plot(x,y,type='l',lty=2,col="blue")
points(x,z,pch=19,col="red")
#I know this legend command doesn't work, but I just want to explain what I want
legend("topleft",c("x","y"),pch=19,lty=2,col=c("red","blue")
So as you can see, I would like to be able to have both points and lines (with the correct type and coloring) in the legend.

You NA values as other argument for pch= and lty=.
legend("topleft",c("x","y"),pch=c(19,NA),lty=c(NA,2),col=c("red","blue"))

Related

using mfrow in R : how do you give each subplot a different y-label and the x-axis one label

I am working in R and I have to make many boxplots. This is a visualization of group differences. I want to relabel the x-axis to only have one title instead of five (one for each subplot). My biggest problem is that I also want the y-axis of all the subplots to have different labels.
This is what I tried so far:
par(mfrow=c(1,5))
lapply(NEW8[,c("gawayf", "humf", "sgamesf", "swtoyf", "kissf")],
function(x) boxplot(x ~ NEW8$PAPA_p4_adhd,col=rainbow(2),
names=c("CN","ADHD"),
ylab=c("gawayf", "humf", "sgamesf", "swtoyf", "kissf")))
All the y-labels are added to each subplots so each subplots has 5 lines of y-axis labels (gawayf, humf, sgamef, swtoyf, kissf), and each plot says what data was used to create the boxplot (PAPA_P4_ADHD).
I want each plots to only have the corresponding y-axis label and the x-axis to have 1 label for all five plots.
This is my current output:
Thank you very much
Instead of lapply try mapply - that will allow to pass different argument to each function call:
par(mfrow=c(1,5))
myBox <- function(x, y, ...) boxplot(x ~ y, col=rainbow(2), names=c("CN", "ADHA"), ...)
mapply(myBox,
x = NEW8[,c("gawayf", "humf", "sgamesf", "swtoyf", "kissf")],
y = list(NEW8$PAPA_p4_adhd), # we make this a list so it has length(1)
ylab = c("gawayf", "humf", "sgamesf", "swtoyf", "kissf"),
xlab = "" # empty x-lab
)
For x-lab you will have to do a trick - start a new empty plot that overlays all of the plots, and only add x-axis:
par(fig=c(0,1,0,1), oma=c(0,0,0,0), mar=par("mar"), new=TRUE)
plot.new()
title(xlab="my x-axis")
NOTE: I didn't try to run this code myself, if anything here doesn't work - please leave a comment and will try to address it.

Plot continuous data with discrete colors

I found some similar questions but the answers didn't solve my problem.
I try to plot a time series of to variables as a scatterplot and using the date to color the points. In this example, I created a simple dataset (see below) and I want to plot all data with timesteps in the 1960ties, 70ties, 80ties and 90ties with one colour respectively.
Using the standard plot command (plot(x,y,...)) it works the way it should, as I try using the ggplot library some strange happens, I guess I miss something. Has anyone an idea how to solve this and generate a correct plot?
Here is my code using the standard plot command with a colorbar
# generate data frame with test data
x <- seq(1,40)
y <- seq(1,40)
year <- c(rep(seq(1960,1969),2),seq(1970,1989,2),seq(1990,1999))
df <- data.frame(x,y,year)
# define interval and assing color to interval
myinterval <- seq(1959,1999,10)
mycolors <- rainbow(4)
colbreaks <- findInterval(df$year, vec = myinterval, left.open = T)
# basic plot
layout(array(1:2,c(1,2)),widths =c(5,1)) # divide the device area in two panels
par(oma=c(0,0,0,0), mar=c(3,3,3,3))
plot(x,y,pch=20,col = mycolors[colbreaks])
# add colorbar
ncols <- length(myinterval)-1
colbarlabs <- seq(1960,2000,10)
par(mar=c(5,0,5,5))
image(t(array(1:ncols, c(ncols,1))), col=mycolors, axes=F)
box()
axis(4, at=seq(0.5/(ncols-1)-1/(ncols-1),1+1/(ncols-1),1/(ncols-1)), labels=colbarlabs, cex.axis=1, las=1)
abline(h=seq(0.5/(ncols-1),1,1/(ncols-1)))
mtext("year",side=3,line=0.5,cex=1)
As I would like to use ggplot package, as I do for other plots, I tried this version with ggplot
# plot with ggplot
require(ggplot2)
ggplot(df, aes(x=x,y=y,color=year)) + geom_point() +
scale_colour_gradientn(colours= mycolors[colbreaks])
but it didn't work the way I thought it would. Obviously, there is something wrong with the color coding. Also, the colorbar looks strange. I also tried it with scale_color_manual and scale_color_gradient2 but I got more errors (Error in continuous_scale).
Any idea how to solve this and generate a plot according to the standard plot 3 including a colorbar.

Axis breaks in ggplot histogram in R [duplicate]

I have data that is mostly centered in a small range (1-10) but there is a significant number of points (say, 10%) which are in (10-1000). I would like to plot a histogram for this data that will focus on (1-10) but will also show the (10-1000) data. Something like a log-scale for th histogram.
Yes, i know this means not all bins are of equal size
A simple hist(x) gives
while hist(x,breaks=c(0,1,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2,3,4,5,7.5,10,15,20,50,100,200,500,1000,10000))) gives
none of which is what I want.
update
following the answers here I now produce something that is almost exactly what I want (I went with a continuous plot instead of bar-histogram):
breaks <- c(0,1,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2,4,8)
ggplot(t,aes(x)) + geom_histogram(colour="darkblue", size=1, fill="blue") + scale_x_log10('true size/predicted size', breaks = breaks, labels = breaks)![alt text][3]
the only problem is that I'd like to match between the scale and the actual bars plotted. There two options for doing that : the one is simply use the actual margins of the plotted bars (how?) then get "ugly" x-axis labels like 1.1754,1.2985 etc. The other, which I prefer, is to control the actual bins margins used so they will match the breaks.
Log scale histograms are easier with ggplot than with base graphics. Try something like
library(ggplot2)
dfr <- data.frame(x = rlnorm(100, sdlog = 3))
ggplot(dfr, aes(x)) + geom_histogram() + scale_x_log10()
If you are desperate for base graphics, you need to plot a log-scale histogram without axes, then manually add the axes afterwards.
h <- hist(log10(dfr$x), axes = FALSE)
Axis(side = 2)
Axis(at = h$breaks, labels = 10^h$breaks, side = 1)
For completeness, the lattice solution would be
library(lattice)
histogram(~x, dfr, scales = list(x = list(log = TRUE)))
AN EXPLANATION OF WHY LOG VALUES ARE NEEDED IN THE BASE CASE:
If you plot the data with no log-transformation, then most of the data are clumped into bars at the left.
hist(dfr$x)
The hist function ignores the log argument (because it interferes with the calculation of breaks), so this doesn't work.
hist(dfr$x, log = "y")
Neither does this.
par(xlog = TRUE)
hist(dfr$x)
That means that we need to log transform the data before we draw the plot.
hist(log10(dfr$x))
Unfortunately, this messes up the axes, which brings us to workaround above.
Using ggplot2 seems like the most easy option. If you want more control over your axes and your breaks, you can do something like the following :
EDIT : new code provided
x <- c(rexp(1000,0.5)+0.5,rexp(100,0.5)*100)
breaks<- c(0,0.1,0.2,0.5,1,2,5,10,20,50,100,200,500,1000,10000)
major <- c(0.1,1,10,100,1000,10000)
H <- hist(log10(x),plot=F)
plot(H$mids,H$counts,type="n",
xaxt="n",
xlab="X",ylab="Counts",
main="Histogram of X",
bg="lightgrey"
)
abline(v=log10(breaks),col="lightgrey",lty=2)
abline(v=log10(major),col="lightgrey")
abline(h=pretty(H$counts),col="lightgrey")
plot(H,add=T,freq=T,col="blue")
#Position of ticks
at <- log10(breaks)
#Creation X axis
axis(1,at=at,labels=10^at)
This is as close as I can get to the ggplot2. Putting the background grey is not that straightforward, but doable if you define a rectangle with the size of your plot screen and put the background as grey.
Check all the functions I used, and also ?par. It will allow you to build your own graphs. Hope this helps.
A dynamic graph would also help in this plot. Use the manipulate package from Rstudio to do a dynamic ranged histogram:
library(manipulate)
data_dist <- table(data)
manipulate(barplot(data_dist[x:y]), x = slider(1,length(data_dist)), y = slider(10, length(data_dist)))
Then you will be able to use sliders to see the particular distribution in a dynamically selected range like this:

How to plot density of two datasets on same scale in one figure?

How to plot the density of a single column dataset as dots? For example
x <- c(1:40)
On the same plot using the same scale of the x-axis and y-axis, how to add another data set as line format which represent the density of another data that represents the equation of
y = exp(-x)
to the plot?
The equation is corrected to be y = exp(-x).
So, by doing plot(density(x)) or plot(density(y)), I got two separated figures. How to add them in the same axis and using dots for x, smoothed line for y?
You can add a line to a plot with the lines() function. Your code, modified to do what you asked for, is the following:
x <- 1:40
y <- exp(-x)
plot(density(x), type = "p")
lines(density(y))
Note that we specified the plot to give us points with the type parameter and then added the density curve for y with lines. The help pages for ?plot, ?par, ?lines would be some insightful reading. Also, check out the R Graph Gallery to view some more sophisticated graphs that generally have the source code attached to them.

How can I plot a histogram of a long-tailed data using R?

I have data that is mostly centered in a small range (1-10) but there is a significant number of points (say, 10%) which are in (10-1000). I would like to plot a histogram for this data that will focus on (1-10) but will also show the (10-1000) data. Something like a log-scale for th histogram.
Yes, i know this means not all bins are of equal size
A simple hist(x) gives
while hist(x,breaks=c(0,1,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2,3,4,5,7.5,10,15,20,50,100,200,500,1000,10000))) gives
none of which is what I want.
update
following the answers here I now produce something that is almost exactly what I want (I went with a continuous plot instead of bar-histogram):
breaks <- c(0,1,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2,4,8)
ggplot(t,aes(x)) + geom_histogram(colour="darkblue", size=1, fill="blue") + scale_x_log10('true size/predicted size', breaks = breaks, labels = breaks)![alt text][3]
the only problem is that I'd like to match between the scale and the actual bars plotted. There two options for doing that : the one is simply use the actual margins of the plotted bars (how?) then get "ugly" x-axis labels like 1.1754,1.2985 etc. The other, which I prefer, is to control the actual bins margins used so they will match the breaks.
Log scale histograms are easier with ggplot than with base graphics. Try something like
library(ggplot2)
dfr <- data.frame(x = rlnorm(100, sdlog = 3))
ggplot(dfr, aes(x)) + geom_histogram() + scale_x_log10()
If you are desperate for base graphics, you need to plot a log-scale histogram without axes, then manually add the axes afterwards.
h <- hist(log10(dfr$x), axes = FALSE)
Axis(side = 2)
Axis(at = h$breaks, labels = 10^h$breaks, side = 1)
For completeness, the lattice solution would be
library(lattice)
histogram(~x, dfr, scales = list(x = list(log = TRUE)))
AN EXPLANATION OF WHY LOG VALUES ARE NEEDED IN THE BASE CASE:
If you plot the data with no log-transformation, then most of the data are clumped into bars at the left.
hist(dfr$x)
The hist function ignores the log argument (because it interferes with the calculation of breaks), so this doesn't work.
hist(dfr$x, log = "y")
Neither does this.
par(xlog = TRUE)
hist(dfr$x)
That means that we need to log transform the data before we draw the plot.
hist(log10(dfr$x))
Unfortunately, this messes up the axes, which brings us to workaround above.
Using ggplot2 seems like the most easy option. If you want more control over your axes and your breaks, you can do something like the following :
EDIT : new code provided
x <- c(rexp(1000,0.5)+0.5,rexp(100,0.5)*100)
breaks<- c(0,0.1,0.2,0.5,1,2,5,10,20,50,100,200,500,1000,10000)
major <- c(0.1,1,10,100,1000,10000)
H <- hist(log10(x),plot=F)
plot(H$mids,H$counts,type="n",
xaxt="n",
xlab="X",ylab="Counts",
main="Histogram of X",
bg="lightgrey"
)
abline(v=log10(breaks),col="lightgrey",lty=2)
abline(v=log10(major),col="lightgrey")
abline(h=pretty(H$counts),col="lightgrey")
plot(H,add=T,freq=T,col="blue")
#Position of ticks
at <- log10(breaks)
#Creation X axis
axis(1,at=at,labels=10^at)
This is as close as I can get to the ggplot2. Putting the background grey is not that straightforward, but doable if you define a rectangle with the size of your plot screen and put the background as grey.
Check all the functions I used, and also ?par. It will allow you to build your own graphs. Hope this helps.
A dynamic graph would also help in this plot. Use the manipulate package from Rstudio to do a dynamic ranged histogram:
library(manipulate)
data_dist <- table(data)
manipulate(barplot(data_dist[x:y]), x = slider(1,length(data_dist)), y = slider(10, length(data_dist)))
Then you will be able to use sliders to see the particular distribution in a dynamically selected range like this:

Resources