将 plot 外的图例移到底部左侧（在 R 中）

Question

I used the likert and ggplot2 package to create this graph. Now, I would like to move the legend at the bottom a little bit to the left, as the last part (Strongly Agree) is not shown in the graph. Unfortunately, I could not find a solution so far. How can I move/shift the legend to the left?

The code:

plot(Likert_Uni_Study_Orientation_OF_V, low.color = "#007CC2", high.color = "#F7971C", neutral.color = "grey", neutral.color.ramp = "white", text.size=9) +
  theme(legend.text=element_text(size=24, margin = margin(r = 30, unit = "pt"))) + 
  theme(legend.direction = "horizontal", legend.position = "bottom") +
  theme(legend.title = element_blank()) +
  ggtitle("Uni Study Orientation – Only Fusha Learners") +
  theme(plot.title = element_text(hjust = 0.5, size =30)) + 
  theme(text = element_text(size = rel(6), color = "black"), axis.text.y = element_text(color = "black")) + 
  theme(axis.text.x = element_text(colour="black", size="30")) + 
  theme(axis.title.x = element_text(vjust=2, size=20, color = "black")) 

Thank you for your help!

Answer 1

Specify a higher value for the width argument when saving to a file.

library(likert)

data(pisaitems)
items29 <- pisaitems[,substr(names(pisaitems), 1,5) == 'ST25Q']
names(items29) <- c("Magazines", "Comic books", "Fiction", 
                    "Non-fiction books", "Newspapers")
l29 <- likert(items29)

plot(l29)

Notice how the legend is clipped. Now send the plot to file and change the default value for width (for png it is 480). You may need a few trials until it appears just right.

png("l29.png", width=480*1.6)
plot(l29)
dev.off()

---

Another option is to place the legend on the right:

plot(l29, legend.position="right")

Answer 2

Addition to the first answer for those who are also new to R and need further explanation

These were my steps:

1. I ran the code in R. The first line contains the changed width (and height). In the second line, I put the plot with all the other features. The third line contains dev.off(). This code saves the plot in.png format in a folder on the laptop.

png("Likert_Uni_Study_Orientation_OF_V.png", width=990*2, height=800)
plot("Likert_Uni_Study_Orientation_OF_V, low.color = "#007CC2", high.color = "#F7971C", neutral.color = "grey", neutral.color.ramp = "white", text.size=10) +
  theme(legend.text=element_text(size=28, margin = margin(r = 30, unit = "pt"))) + 
  theme(legend.direction = "horizontal",legend.position = "bottom") +
  theme(legend.title = element_blank()) + 
  ggtitle("Uni Study Orientation – Only Fusha Learners") +
  theme(plot.title = element_text(hjust = 0.5, size =40)) +
  theme(text = element_text(size = rel(7.5), color = "black"), axis.text.y = element_text(color = "black")) +
  theme(axis.text.x = element_text(colour="black", size="30")) +
  theme(axis.title.x = element_text(vjust=2, size=20, color = "black"")
dev.off()

2. I had to find out, where R saved my plot. For that, I only used the search function on my laptop. In my case, it was saved in "My PC" --> "Documents".

Answer 3

You can use cowplot as explained here Center legend in ggplot2 relative to image

(link given by @steph in the comments)

this one also works when the legend is much too big for ggplot to show it correctly at the bottom.

a= plot(l29)   
library (cowplot)

p1_legend <- get_legend(a+ theme(legend.position = 'right'))
plot_grid(a + theme(legend.position = 'none'), p1_legend,
      nrow = 2, rel_heights = c(1, 1))