如何从metafor包中进一步格式化R中的森林图？

install.packages("metafor")
library(metafor)

# 安装和加载metafor包
install.packages("metafor")
library(metafor)

# 准备数据
effect_sizes <- c(0.5, 0.8, 1.2)
standard_errors <- c(0.1, 0.2, 0.3)
study_names <- c("Study 1", "Study 2", "Study 3")
data <- data.frame(effect_size = effect_sizes, standard_error = standard_errors, study_name = study_names)

# 计算权重
data$weight <- 1 / data$standard_error^2

# 创建森林图对象
forest_obj <- forest(effect_size, standard_error, data = data, slab = study_name, weights = weight)

# 格式化森林图
forest_obj <- addpoly(forest_obj, mlab = 0, row = 1, col = "gray")
forest_obj <- addlines(forest_obj, mlab = 0, row = 1, col = "black")
forest_obj <- addbox(forest_obj, mlab = 0, row = 1, col = "black")

# 添加其他元素
forest_obj <- addstudy(forest_obj, mlab = 0, row = 1)
forest_obj <- addci(forest_obj, mlab = 0, row = 1)
forest_obj <- addfit(forest_obj, mlab = 0, row = 1)

# 显示和保存森林图
print(forest_obj)
savefig("forest_plot.png")