Is it possible to obtain the appropriate value of inset automatically so that the left corner of legend will always be just outside of the top right corner of plot?
In the plot below I had to try several values for inset manually. It would be nice to not have to do it manually since I have to make multiple plots.
graphics.off()
windows(width = 5, height = 5)
set.seed(42)
par(mar = c(5,5,1,10))
plot(rnorm(50,15,5), rnorm(50,15,3),
xlim = c(0,30), ylim = c(5,25),
pch = 19, col = c("red","blue"))
par(xpd = TRUE)
legend("topright", inset = c(-.80, 0),
pch = 19, col = c("red","blue"),
legend = c("LEGEND 1","Second Legend"))
After the plot call, before adding the legend, use par("usr")* to extract the coordinates of the plotting region.
Then, instead of positioning the legend using a 'keyword' and inset, use x and y with the top-right coordinates of the plotting region obtained from par("usr"). Adjust x with a suitable coefficient.
coord <- par("usr")
legend(x = coord[2] * 1.05, y = coord[4],
pch = 19, col = c("red", "blue"),
legend = c("LEGEND 1", "Second Legend"))
And just for fun, a more convoluted alternative.
After plotting, call legend with position topright, but without plotting it to the device (plot = FALSE), and assign it to an object.
Extract the left x and the top y coordinate of the legend box, and its width (see Value section in ?legend), to be used in x and y in legend:
leg <- legend("topright", pch = 19, col = c("red", "blue"),
legend = c("LEGEND 1", "Second Legend"),
plot = FALSE)
legend(x = (leg$rect$left + leg$rect$w) * 1.05, y = leg$rect$top,
pch = 19, col = c("red", "blue"),
legend = c("LEGEND 1", "Second Legend"))
*From ?par
usr A vector of the form c(x1, x2, y1, y2) giving the extremes of the user coordinates of the plotting region.
The position calculations that are made when inset parameter(s) have been specified, are in fact based on par("usr") (see line 188-199 in the legend code).
Related
I ran a distance-based RDA using capscale() in the vegan library in R and I am trying to plot my results as a custom triplot. I only want numeric or continuous explanatory variables to be plotted as arrows/vectors. Currently, both factors and numeric explanatory variables are being plotted with arrows, and I want to remove arrows for factors (site and year) and plot centroids for these instead.
dbRDA=capscale(species ~ canopy+gmpatch+site+year+Condition(pair), data=env, dist="bray")
To plot I extracted % explained by the first 2 axes as well as scores (coordinates in RDA space)
perc <- round(100*(summary(spe.rda.signif)$cont$importance[2, 1:2]), 2)
sc_si <- scores(spe.rda.signif, display="sites", choices=c(1,2), scaling=1)
sc_sp <- scores(spe.rda.signif, display="species", choices=c(1,2), scaling=1)
sc_bp <- scores(spe.rda.signif, display="bp", choices=c(1, 2), scaling=1)
I then set up a blank plot with scaling, axes, and labels
dbRDAplot<-plot(spe.rda.signif,
scaling = 1, # set scaling type
type = "none", # this excludes the plotting of any points from the results
frame = FALSE,
# set axis limits
xlim = c(-1,1),
ylim = c(-1,1),
# label the plot (title, and axes)
main = "Triplot db-RDA - scaling 1",
xlab = paste0("db-RDA1 (", perc[1], "%)"),
ylab = paste0("db-RDA2 (", perc[2], "%)"))
Created a legend and added points for site scores and text for species
pchh <- c(2, 17, 1, 19)
ccols <- c("black", "red", "black", "red")
legend("topleft", c("2016 MC", "2016 SP", "2018 MC", "2018 SP"), pch = pchh[unique(as.numeric(as.factor(env$siteyr)))], pt.bg = ccols[unique(as.factor(env$siteyr))], bty = "n")
points(sc_si,
pch = pchh[as.numeric(as.factor(env$siteyr))], # set shape
col = ccols[as.factor(env$siteyr)], # outline colour
bg = ccols[as.factor(env$siteyr)], # fill colour
cex = 1.2) # size
text(sc_sp , # text(sc_sp + c(0.02, 0.08) tp adjust text coordinates to avoid overlap with points
labels = rownames(sc_sp),
col = "black",
font = 1, # bold
cex = 0.7)
Here is where I add arrows for explanatory variables, but I want to be selective and do so for numeric variables only (canopy and gmpatch). The variables site and year I want to plot as centroids, but unsure how to do this. Note that the data structure for these are definitely specified as factors already.
arrows(0,0, # start them from (0,0)
sc_bp[,1], sc_bp[,2], # end them at the score value
col = "red",
lwd = 2)
text(x = sc_bp[,1] -0.1, # adjust text coordinate to avoid overlap with arrow tip
y = sc_bp[,2] - 0.03,
labels = rownames(sc_bp),
col = "red",
cex = 1,
font = 1)
#JariOksanen thank you for your answer. I was able to use the following to fix the problem
text(dbRDA, choices = c(1, 2),"cn", arrow=FALSE, length=0.05, col="red", cex=0.8, xpd=TRUE)
text(dbRDA, display = "bp", labels = c("canopy", "gmpatch"), choices = c(1, 2),scaling = "species", arrow=TRUE, select = c("canopy", "gmpatch"), col="red", cex=0.8, xpd = TRUE)
#JariOksanen thank you for your answer. I was able to use the following to fix the problem
text(dbRDA, choices = c(1, 2),"cn", arrow=FALSE, length=0.05, col="red", cex=0.8, xpd=TRUE)
text(dbRDA, display = "bp", labels = c("canopy", "gmpatch"), choices = c(1, 2),scaling = "species", arrow=TRUE, select = c("canopy", "gmpatch"), col="red", cex=0.8, xpd = TRUE)
I'm trying to use vegan package in R to create NMDS plots for my research. I'm having problems placing the legend in the correct area, however. The legend always covers some of the points and gets cut off by the outline of the plot. Anyone have any ideas of how I could format the legend outside of the plot area, or move it so that it doesn't cover up any points?
Here is an exported image of what my graph looks like now, with part of the legend missing and covering up some points.
Here is the script I've been using:
op <- ordiplot(nmds, type = 'n')
cols = c('darkred', 'darkgreen', 'darkblue', 'yellow', 'pink', 'lightgreen', 'lightblue', 'black')
points(nmds, cex = 2, pch = 16, col = cols[coral_ENV$Year])
ordispider(nmds, groups = coral_ENV$Year, label = TRUE, label.size = 0.2)
ordihull(nmds, groups = coral_ENV$Year, lty = 'dotted')
legend("topleft", inset = 0.03, pch = 16, col = cols, text.width = 0.05, legend = levels(coral_ENV$Year))
I'm pretty new to R so I'd appreciate any help!
Just a minor question. I am trying to make a legend for the following plot.
# fitting the linear model
iris_lm = lm(Petal.Length ~ Sepal.Length, data = iris)
summary(iris_lm)
# calculating the confidence interval for the fitted line
preds = predict(iris_lm, newdata = data.frame(Sepal.Length = seq(4,8,0.1)),
interval = "confidence")
# making the initial plot
par(family = "serif")
plot(Petal.Length ~ Sepal.Length, data = iris, col = "darkgrey",
family = "serif", las = 1, xlab = "Sepal Length", ylab = "Pedal Length")
# shading in the confidence interval
polygon(
c(seq(8,4,-0.1), seq(4,8,0.1)), # all of the necessary x values
c(rev(preds[,3]), preds[,2]), # all of the necessary y values
col = rgb(0.2745098, 0.5098039, 0.7058824, 0.4), # the color of the interval
border = NA # turning off the border
)
# adding the regression line
abline(iris_lm, col = "SteelBlue")
# adding a legend
legend("bottomright", legend = c("Fitted Values", "Confidence Interval"),
lty = c(1,0))
Here's the output so far:
My goal is to put a box in the legend next to the "Confidence Interval" tab, and color it in the same shade that it is in the picture. Naturally, I thought to use the pch parameter. However, when I re-run my code with the additional legend option pch = c(NA, 25), I get the following:
It is not super noticeable, but if you look closely at the padding on the left margin of the legend, it actually has decreased, and the edge of the border is now closer to the line than I would like. Is there any way to work around this?
That's a curious behavior in legend(). I'm sure someone will suggest a ggplot2 alternative. However, legend() does offer a solution. This solution calls the function without plotting anything to capture the dimensions of the desired rectangle. The legend is then plotted with the elements you really want but no enclosing box (bty = "n"). The desired rectangle is added explicitly. I assume you mean pch = 22 to get the filled box symbol. I added pt.cex = 2 to make it a bit larger.
# Capture the confidence interval color, reusable variables
myCol <- rgb(0.2745098, 0.5098039, 0.7058824, 0.4)
legText <- c("Fitted Values", "Confidence Interval")
# Picking it up from 'adding a legend'
ans <- legend("bottomright", lty = c(1,0), legend = legText, plot = F)
r <- ans$rect
legend("bottomright", lty = c(1,0), legend = legText, pch = c(NA,22),
pt.bg = myCol, col = c(1, 0), pt.cex = 2, bty = "n")
# Draw the desired box
rect(r$left, r$top - r$h, r$left + r$w, r$top)
By the way, I don't think this will work without further tweaking if you place the legend on the left side.
This question already has answers here:
How can I plot with 2 different y-axes?
(6 answers)
Closed 6 years ago.
i'm having troubles in a multi axis barplot. I have an X,Y axis with bars and dots in the same graph. The point is that I have to shown both of them in different scales
While I can shown both (bars and dots) correctly, the problem comes when I try to set different scales in left and right axis. I dont know how to change the aditional axis scale, and how to bind the red dots to the right axis, and the bars to the left one.
This is my code and what I get:
labels <- value
mp <- barplot(height = churn, main = title, ylab = "% churn", space = 0, ylim = c(0,5))
text(mp, par("usr")[3], labels = labels, srt = 45, adj = c(1.1,1.1), xpd = TRUE, cex=.9)
# Population dots
points(popul, col="red", bg="red", pch=21, cex=1.5)
# Churn Mean
media <- mean(churn)
abline(h=media, col = "black", lty=2)
# Population scale
axis(side = 4, col= "red")
ylim= c(0,50)
ylim= c(0,5)
What I want is to have left(grey) axis at ylim=c(0,5) with the bars bound to that axis. And the right(red) axis at ylim=c(0,50) with the dots bound to that axis...
The goal is to represent bars and points in the same graph with diferent axis.
Hope I explained myself succesfully.
Thanks for your assistance!
Here is a toy example. The only "trick" is to store the x locations of the bar centers and the limits of the x axis when creating the barplot, so that you can overlay a plot with the same x axis and add your points over the centers of the bars. The xaxs = "i" in the call to plot.window indicates to use the exact values given rather than expanding by a constant (the default behavior).
set.seed(1234)
dat1 <- sample(10, 5)
dat2 <- sample(50, 5)
par(mar = c(2, 4, 2, 4))
cntrs <- barplot(dat1)
xlim0 <- par()$usr[1:2]
par(new = TRUE)
plot.new()
plot.window(xlim = xlim0, ylim = c(0, 50), xaxs = "i")
points(dat2 ~ cntrs, col = "darkred")
axis(side = 4, col = "darkred")
I want to make a legend on my graph, which is generated by plot() function. The original legend() function will generate a list which has only 1 column. How can I make a legend which has 2 columns?
I could not find a way to do that within a single call to legend for standard plots.
Here's an option, drawing two separate legends: one with lines and points, one with labels. x.intersp can be used to tweak distance between labels and lines.
plot(cumsum(runif(n = 100)))
# draw legend with lines and point but without labels and box. x.intersp controls horizontal distance between lines
L = legend(x = 'bottom', legend = rep(NA,4), col=1:2, lty=c(1,1,2,2), ncol=2, bty='n', x.intersp=0.5, pch=c(1,2,1,2), inset=0.02)
# use position data of previous legend to draw legend with invisble lines and points but with labels and box. x.intersp controls distance between lines and labels
legend(x = L$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