Two questions of R circlepack plot ：

Question

Two questions of R circlepack plot ：

1. the result always not real circular (it always show in ellipse, I have to adjust the plot window size in Rstudio ....) . Is the any way to hadle it ?

2. The position of circular and sub circular will be changed when rerun the code ? How to fix it ?

   library(ggraph)
    library(igraph)
    library(dplyr)
    library(tidyverse)
   
    md <- data.frame(category = c('FDM','FDM','FDM','LCD','LCD','LCD'),
                          item =c('A1','B1','C1','A','B','C'),
                     amount = c(1,2,3,4,3,1))
    md_sum <- md %>% group_by(category) %>% summarise(amount =sum(amount)) %>% rename('item'='category')
   
    md_v <- rbind(md[,c(2:3)],md_sum)
   
    pt <- igraph::graph_from_data_frame(md,vertices = md_v)
   
   
    ggraph(pt,layout = 'circlepack', weight =amount)+
      geom_node_circle(aes(fill=depth))+
     geom_node_label(aes(label = paste0(name,'\n',amount )))+theme_void()