1

here is my current code:

vec2<- c(10.810811, 18.146718, 25.096525, 26.640927, 16.216216,  3.088803)
b<-barplot(as.matrix(vec2), ylab = "Total Percentage", xlab="studies", col = c("red", "yellow", "green", "violet", "skyblue", "cyan"), width=1)
# Find the top y position of each block
ypos <- apply(as.matrix(vec2), 2, cumsum)
# Move it downwards half the size of each block
ypos1 <- ypos - vec2/2
ypos1 <- t(ypos1)
text(b, ypos1, labels=round(vec2))

using my current code how do I add text to this barplot on the right outside of the color coded part of the plot? I want text in the middle and outside to the right of the plot? Also how to I make my barplot skinnier?

Genetics
  • 279
  • 2
  • 11
  • Have you looked at `?mtext`? – IRTFM Dec 04 '15 at 20:37
  • I have and and dont quite understand how mtext is different than text – Genetics Dec 04 '15 at 20:39
  • 1
    It's designed for writing in the margins. Oh wait. you also need to read `?par` ... especially the `mar` parameter, and maybe also `xpd`. – IRTFM Dec 04 '15 at 20:45
  • You can also use `text`, but you'll need to add `xpd=TRUE` to allow text outside the plot area to show up. For example, add this to your plot: `text(c(0.2, 0.5, 0.75, 1, 1.3), 33, "Some Text", xpd=TRUE, col=grey(seq(0,0.5,length.out=5)))` – eipi10 Dec 04 '15 at 23:09

2 Answers2

2

I dealt with a similar situation recently. I think my solution should be applicable to your situation as well. I accomplished this by using the layout() function to create a multi-pane plot, in which the legend() was placed in a narrow empty pane.

The important part of the code I used is as follows

#####################
# Set up the plots

BARPLOT_COLORS<-c("blue","purple","red")

# setup the matrix for the plot layout
# it is easier to create this in a csv file in Excel, etc., then read it into R as a matrix
# here is the dput() code for the matrix I made
Counts_matrix<-structure(c(1L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 1L, 2L, 
                                     2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 1L, 2L, 2L, 2L, 2L, 2L, 3L, 
                                     3L, 3L, 3L, 3L, 1L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L),
                                   .Dim = c(11L,4L), 
                                   .Dimnames = list(NULL, c("V1", "V2", "V3", "V4")))
# looks like this
# > Counts_matrix
# V1 V2 V3 V4
# [1,]  1  1  1  1
# [2,]  2  2  2  2
# [3,]  2  2  2  2
# [4,]  2  2  2  2
# [5,]  2  2  2  2
# [6,]  2  2  2  2
# [7,]  3  3  3  3
# [8,]  3  3  3  3
# [9,]  3  3  3  3
# [10,]  3  3  3  3
# [11,]  3  3  3  3
# the numbers here correspond to contiguous areas in which the plots will be placed
# in the numerical order specified
# since the OP wants the legend on the right side, make a matrix like this with 1's along that side 


# setup the panel layout by passing the matrix to layout()
layout(Counts_matrix)
# layout.show(max(Counts_matrix))  # use this to preview the layout

par(mar=c(0,0,4,0)) # need to set this for some reason
# on mar: A numerical vector of the form c(bottom, left, top, right) which gives the number of lines of margin to be specified on the four sides of the plot. 
# The default is c(5, 4, 4, 2) + 0.1.

# call blank plot to fill the first panel
plot(1,type='n',axes=FALSE,xlab="",ylab="",main = "Quality Counts",cex.main=2) 

# set up the Legend in the first panel
legend("bottom",legend=c("Good","Bad","Ugly"),fill=BARPLOT_COLORS,bty = "n",ncol=length(BARPLOT_COLORS),cex=1.0)

# set the mar for the remaining panels
par(mar=c(6,5,0,4))
# create barplot for the two matrices
barplot(Raw_Counts,horiz = T,col=BARPLOT_COLORS,border=NA,las=1,cex.names=1,xlab="Number of counts (millions)")
barplot(Pcnt_Counts,horiz = T,col=BARPLOT_COLORS,border=NA,las=1,cex.names=1,xlab="Percent of counts")

I did a lot of reading to figure this one out; some relevant links can be found here:

http://seananderson.ca/courses/11-multipanel/multipanel.pdf

Common legend for multiple plots in R

The entire code that I used can be found here:

https://github.com/stevekm/Bioinformatics/blob/master/scripts/alignment_summary_muti_panel_barplot.R

You should be able to copy/paste that right into RStudio and run it to see how it works

Community
  • 1
  • 1
user5359531
  • 3,217
  • 6
  • 30
  • 55
1

If you don't want to install any packages, you can do the following...

text(x = 1.25, y = 50, labels = "Text Goes Here", srt = 270, xpd=T)

x determines offset in x
y determines offset in y
labels are what you want to display
srt sets an angle that is applied to it (90 will flip what I have posted)
xpd allows text to extend past border (try this as False to see what I'm talking about)

UseR10085
  • 7,120
  • 3
  • 24
  • 54
JCB
  • 35
  • 5