Legends in barplot not appearing properly - r

heights1=c(5,5,4.5,4,4,4,4.5,2,4,4)
opar <- par(lwd = 0.3)
barplot(heights1,xlim=c(0,3), ylim=c(0,5), width=0.1,
main="Langauges(Verbal & Non-verbal)",
names.arg=c("Spanish", "Speak" , "English","Speak", "Hindi",
"Speak", "Arabic", "Speak", "Body Lang", "Speak"), ylab="Skill level ",
xlab="Language starting with mostly used", col=c("darkblue","red"),
cex.names=0.7,space=c(2,0,2,0,2,0,2,0,2,0))
legend("top", c("darkblue","red"), c("reading/Writing", "Speaking") );
Blue is for "reading/writing" and red is for "speaking". How do I make correction in legend? (I do not want to define legend inside barplot function)

You can use the fill argument for your colors. As with David Robinson's answer, I would also suggest placing the legend in the top right in this case.
legend("topright",
legend = c("reading/Writing", "Speaking"),
fill = c("darkblue", "red"))
Looking at some of your other questions, you might also want to spend some time getting your data into a more appropriate form before plotting.
Here's an example:
Here is your data:
heights1 = c(5, 5, 4.5, 4, 4, 4, 4.5, 2, 4, 4) # Your data
Here is your data as a matrix with appropriate dimnames
mydata <- matrix(heights1, ncol = 2, byrow = TRUE,
dimnames = list(c("Spanish", "English", "Hindi",
"Arabic", "Body Lang"),
c("Reading/Writing", "Speaking")))
mydata # Much more meaningful to look at than a simple vector
# Reading/Writing Speaking
# Spanish 5.0 5
# English 4.5 4
# Hindi 4.0 4
# Arabic 4.5 2
# Body Lang 4.0 4
Define your colors (optional, but useful if you are working with more than just a pair of bars per group)
colors <- c("darkblue", "red") # Define the colors you're using
Plot your data adding a little bit of extra space at the top and suppressing your axes. Not sure why you don't want to include the legend at this stage, but it could easily be done by adding the following arguments: legend.text = TRUE, args.legend = list(x = "topright", bty = "n")
barplot(t(mydata), beside = TRUE, col = colors,
ylim = c(0, 6), axes = FALSE,
xlab = "Language starting with mostly used",
main = "Languages (Verbal & Non-verbal)")
Reintroduce your y-axis and add your legend
axis(2, at = 0:5, labels = 0:5)
legend("topright", colnames(mydata), fill = colors, bty = "n")

Change your legend line to
legend("topright", c("reading/Writing", "Speaking"), col=c("darkblue","red"), lwd=10);
The lwd argument says the legend should have lines of 10 pixel thickness of each of the corresponding colors. It's a good idea to use "topright" rather than "top" in your case so that the legend doesn't appear under the bars.

Related

R plot legend: Reduce space between legend columns

I am using vegan library to make some plots, with this code:
raremax <- min(colSums(mydata))
col <- palette()
lty <- c("solid", "dashed", "longdash", "dotdash")
pars <- expand.grid(col = col, lty = lty, stringsAsFactors = FALSE)
out <- with(pars[1:18, ], rarecurve(mydata, step = 100, sample = raremax,
cex =0.6, ylab="OTUs", label=F, col=col, lty=lty, lwd=2))
Then I add a legend using this code:
legend("bottomright", names(mydata), col=pars[1:18,1], lty= pars[1:18,2],
lwd=2, cex=0.5, xjust=1, ncol=2, x.intersp=0.5, y.intersp=0.5, bg="white")
The resulting graph looks like this:
I would like to reduce the space between legend columns, also reducing the size of the legend box, but I can't find a way to do that.
Anyone could provide me some help?
A combination of the legend() parameters "x.intersp" and "text.width" should be helpful.
Decreasing "x.intersp" (default value = 1, for me 0.25 looked good) should move your the legend labels closer to their respective points. Decreasing "text.width" (default value=NULL, for me 0.045 looked good) moves the columns closer together.

How to consistently skip (or not skip) x axis labels in R base graphics

I want to create a figure where for various reasons I need to specify the axis labels myself. But when I specify my labels (some have one digit, some two digits) R suppresses every other two-digit label because it decides there isn't enough room to show them all, but it leaves all of the one-digit labels, leaving the axis looking lopsided.
Is there a way to suppress labels consistently across the whole axis, based on whether any of them need to be skipped? Note: I have a lot of plots with varying scales, so I was looking for something I could use for all of them - I don't want to render all the labels for every plot, or to skip every other label in every plot. Suppressing labels will be desirable for some plots and not for others. I just want to skip every other label consistently, if that's what R chooses to do for the particular plot.
(Here is an example figure of what I mean. What I want is for the "6%" label to also be suppressed in the x axis.)
Example code:
library(labeling)
df <- data.frame("estimate" = c(9.81, 14.29, 12.94),
"lower" = c(4.54, 6.25, 5.12),
"upper" = c(12.85, 20.12, 15.84))
ticks <- extended(min(df$lower), max(df$upper), m = 5, only.loose = TRUE,
Q=c(2, 5, 10))
png("examplePlot.png", width = 1200, height = 900, pointsize = 10, res = 300)
bars <- barplot(df$estimate, horiz = TRUE, col = "white", border = NA,
xlim = c(min(ticks), max(ticks)), xaxt = "n", main = "Example")
arrows(df$lower, bars, df$upper, bars, code = 3, angle = 90, length = 0.03)
points(df$estimate, bars, pch = 20)
tickLabels <- paste(ticks, "%", sep = "")
axis(1, at=ticks, labels = tickLabels, cex.axis=1)
axis(2, at = bars, labels = c("c", "b", "a"), lwd = 0, las = 2)
dev.off()
This depends on the size of the plot, so you'll have to plot each label separately:
axis(1, lwd.ticks = 1, labels = FALSE, at = ticks) # plot line and ticks
i <- seq(1,length(ticks),2) # which labels to plot
for(ii in i)
axis(1, at = ticks[ii], labels = tickLabels[ii], cex.axis = 1, lwd = 0)

How to change the legend title and position in a lattice plot

I'm using lsmip from lsmeans to plot my model,
library(lsmeans)
PhWs1 <- lsmip(GausNugget1, Photoperiod:Ws ~ Month,
ylab = "Observed log(number of leaves)", xlab = "Month",
main = "Interaction between Photoperiod and Water stress over the months (3 photoperiods)",
par.settings = list(fontsize = list(text = 15, points = 10)))
but I was not able to get a suggestion on the internet on how to handle the legend position, size, title, etc.
I used trellis.par.get() to see the parameters but I could not find the one related to my issue. As you can see from the graph, the legend should be "Photoperiod*Ws" but Ws is not visible.
I see two possibly complementing alternatives to approach this issue. The first would be to create a fully customized legend and pass it on to the key argument of xyplot (which lsmip is heavily based on). Here is an example taken from ?lsmip to clarify my point.
## default trellis point theme
trellis_points <- trellis.par.get("superpose.symbol")
## create customized key
key <- list(title = "Some legend title", # legend title
cex.title = 1.2,
x = .7, y = .9, # legend position
points = list(col = trellis_points$col[1:2], # points
pch = trellis_points$pch[1:2],
cex = 1.5),
text = list(c("A", "B"), cex = .9)) # text
## create results and extract lattice plot
d <- lsmip(warp.lm, wool ~ tension, plotit = FALSE,
main = "Some figure title", key = key)
p <- attr(d, "lattice")
p
As you can see, setting up a customized legend let's you modify all the different components of the legend - including labels, text and symbol sizes, legend spacing, etc. Have a deeper look at the key argument described in ?xyplot which describes the various modification options in detail.
Now, if you have a long legend title and you do not want to include the legend inside the plot area, you could also define separate viewports, thus allowing the legend to occupy more space at the right margin. Note the use of update to remove the initially created legend from p and the subsequent assembly of the single figure components using grid functionality.
## remove legend from figure
p <- update(p, legend = NULL)
## assemble figure incl. legend
library(grid)
png("plot.png", width = 14, height = 10, units = "cm", res = 300)
grid.newpage()
## add figure without legend
vp0 <- viewport(x = 0, y = 0, width = .75, height = 1,
just = c("left", "bottom"))
pushViewport(vp0)
print(p, newpage = FALSE)
## add legend
upViewport(0)
vp1 <- viewport(x = .7, y = 0, width = .3, height = 1,
just = c("left", "bottom"))
pushViewport(vp1)
draw.key(key, draw = TRUE)
dev.off()

How to make R legend with 2 columns?

I want to make a legend on my graph, which is generated by plot() function. The original legend() function will generate a list which has only 1 column. How can I make a legend which has 2 columns?
I could not find a way to do that within a single call to legend for standard plots.
Here's an option, drawing two separate legends: one with lines and points, one with labels. x.intersp can be used to tweak distance between labels and lines.
plot(cumsum(runif(n = 100)))
# draw legend with lines and point but without labels and box. x.intersp controls horizontal distance between lines
L = legend(x = 'bottom', legend = rep(NA,4), col=1:2, lty=c(1,1,2,2), ncol=2, bty='n', x.intersp=0.5, pch=c(1,2,1,2), inset=0.02)
# use position data of previous legend to draw legend with invisble lines and points but with labels and box. x.intersp controls distance between lines and labels
legend(x = L$rect$left, y = L$rect$top, legend = c('Group A', 'Group B'), col=rep(NA,2), lty=c(1,1), ncol=1, x.intersp = 3, bg = NA)
Check this:
library(lattice)
myPCH <- 15:17
Data <- rnorm(50)
Index <- seq(length(Data))
xyplot(Data ~ Index,
pch = myPCH, col=1:2,
key = list(space = "right", adj=1,
text = list(c("a", "b", "c"), cex=1.5),
points = list(pch = myPCH),
points = list(pch = myPCH,col=2)))
It looks like Victorp answered this in the comments of the original post. The ncol argument in the legend function works for me:
legend(locator(1), legend=c("name1","name2", "name3", "name4"), lty=2, col=c("black", "blue", "dark green", "orange"), ncol=2)
enter image description here

Combine different key element types (rectangles, lines, ...) in lattice plot in R

At first I thought this would be trivial, but I could not figure out how to combine rectangles with lines in the legend of a lattice plot. Consider the following example:
library(latticeExtra)
xyplot(rnorm(10) ~ 1:10,
key=list(rectangles=list(size=2, border=F),
text=list(c("Zero", "One", "Two"), col="black"),
col=c("black", "lightgrey", "darkgrey"), divide=1, columns=1,
x=0.01, y=0.95, corner=c(0,1) ),
panel=function(x,...){
panel.abline(v=3, lty="dashed")
panel.xblocks(x,x>5, col="lightgrey")
panel.xblocks(x,x>7, col="darkgrey")
panel.xyplot(x, ...) } )
Instead of 3 rectangles, I would like to have 2 rectangles filled with the appropriate colours, and one dashed line above or below these two rectangles. If I provide a lines argument, then both lines and rectangles will be drawn for all elements (i.e. there will be 2 rectangles and 2 lines simultaneously next to each other).
How can I set up the legend key so that I get this mix of "symbols"? That is, how can I get one dashed line and two rectangles with the appropriate text and colours?
Any help is greatly appreciated! My apologies if this is trival. Please help me see the obvious! :)
This is a rather late answer but it is something I still do. One approach is to use auto.key in the function and then modify the lattice object with update(obj, key = newKey). A more general approach, as suggested by #josh-obrien, is to use the grid functions that under lattice. However, this typically requires empirical tweaking of the coordinates as can be seen in the need to use 3 decimal places of precision to place the dashed lines.
# relative position may be sensitive to absolute sizes
library(latticeExtra)
dev.new(width = 5, height = 5)
set.seed(1234)
# same code as in question, re-written a little bit
# using "transparent" for the 1st of the three rectangles
# using a grid call in the panel function to place the dashed line
xyplot(rnorm(10) ~ 1:10,
key = list(rectangles = list(size = 2, border = FALSE,
col = c("transparent", "lightgrey", "darkgrey")),
text = list(c("Zero", "One", "Two"), col = "black"),
columns = 1, corner = c(0.01, 0.95)),
panel = function(x,...) {
panel.abline(v = 3, lty = "dashed")
panel.xblocks(x, x > 5, col = "lightgrey")
panel.xblocks(x, x > 7, col = "darkgrey")
panel.xyplot(x, ...)
grid::grid.lines(c(0.04, 0.07), c(0.935, 0.935),
gp = gpar(lty = "dashed", col = "black"))
}
)
[![plot with combined elements in legend][1]][1]
[1]: https://i.stack.imgur.com/K7AJN.png

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