ggplot grobs align with tableGrob
ggplot2, gridextra, gtable
Solution
I had a similar question as above when trying to make something like a forestplot in R using ggplot2 and didn't find any of the other solutions fit my needs. The answer above didn't work for me - the table didn't show up. So I hacked together a codewise not that pretty solution, but I actually kind of like the cleanliness visual output.
The things I like about this solution are:
- I aligned a set of custom text not in a table, but just in a figure on the right, where the alignment matched for each text entry and each label in the figure.
- I used a centered ggtitle to align a "column heading" above each set of text. These could be strings of any kind (in my actual use, I had point estimates and confidence intervals).
library(gridExtra)
library(ggplot2)
dat <- data.frame(
label = c("A", "B", "C"),
point_est = c(1,2,3),
lb_ci = c(.5, 1.5, 2.5),
ub_ci = c(1.5, 2.5, 3.5),
n = c(50, 100, 150),
total = c(75, 150, 200)
)
plot1 <- ggplot(dat, aes(x=point_est, y=label)) +
geom_point() +
geom_errorbarh(aes(xmin=lb_ci, xmax=ub_ci), height=.5) +
ggtitle("Some measure") +
ylab(NULL) + xlab("some effect estimate")
tab_base <- ggplot(dat, aes(y=label)) +
ylab(NULL) + xlab(" ") +
theme(plot.title = element_text(hjust = 0.5, size=12), ## centering title on text
axis.text.x=element_text(color="white"), ## need text to be printed so it stays aligned with figure but white so it's invisible
axis.line=element_blank(),
axis.text.y=element_blank(),axis.ticks=element_blank(),
axis.title.y=element_blank(),legend.position="none",
panel.background=element_blank(),panel.border=element_blank(),panel.grid.major=element_blank(),
panel.grid.minor=element_blank(),plot.background=element_blank())
tab1 <- tab_base +
geom_text(aes(x=1, label=n)) +
ggtitle("n")
tab2 <- tab_base +
geom_text(aes(x=1, label=total)) +
ggtitle("total")
lay <- matrix(c(1,1,1,1,1,1,2,3), nrow=1)
grid.arrange(plot1, tab1, tab2, layout_matrix = lay)
Problem
I'm having difficulty to find solution for aligning ggplot grob and table grob. I tried to follow the instruction here but still didn't give the results I wanted. ``` library(grid) library(gridExtra) library(ggplot2) library(tibble) library(gtable) dat <- tibble::rownames_to_column(mtcars, "car") #convert rownames to first col plot1 <- ggplot(dat, aes(car, mpg)) + geom_bar(stat = "identity") + coord_flip() g1 <- ggplotGrob(plot1) tb1 <- tableGrob(dat$cyl) g1 <- gtable_add_cols(g1, unit(0.2, "npc")) g1 <- gtable_add_grob(g1, grobs = tb1, t=3, l=ncol(g1), b=6, r=ncol(g1)) grid.newpage() grid.draw(g1) ``` I would like that each cell in the table be aligned to related bar in histogram, but still couldn't understand how the t,l,b,r be implemented from the layout.This is the output I got