Combining Forest Plots in One Plot I am trying to combine 4 forest plots into 1 matrix type plot output with 2 columns and 2 rows.
I have tried grid.arrange multiple times but I continue to get "only grobs allowed in list."

*

*The meta functions are done using metacont as my data is continuous

My code is as follows:
plot_ma<-forest(ma_meta, xlab = "title")
plot_m1<-forest(m1_meta, xlab = "title")
plot_m2<-forest(m2_meta, xlab = "title")
plot_ab<-forest(ab_meta, xlab = "title")

I would like for these to be combined in a matrix format so that my output can be one matrix of the 4 plots.
Thank you

You could try:
library(gridExtra)
grid.arrange(plot_ma, plot_m1, plot_m2, plot_ab, ncol=2,top="Your Title")

or with base graphics:
par(mfrow = c(4, 1))
forest(ma_meta, xlab = "title")
forest(m1_meta, xlab = "title")
forest(m2_meta, xlab = "title")
forest(ab_meta, xlab = "title")
par(mfrow = c(1, 1)) #reset this parameter

