I have created a map that iterates through counties and adds a color and a pattern based on the great ggpattern r package, however I cannot figure out how to create a legend to add to the map with the cooresponding colors and hex patterns. The reason i’m iterating and adding each individual county is so i can eventually control which patterns go with certain counties. If there is a better way i am open to that as well!

library(ggplot2)
library(sf)
library(tidyverse)
library(ggpattern)
library(cowplot)

nc <- st_read(system.file("shape/nc.shp", package="sf"))


nc<-nc%>%mutate(row_id=row_number())

ids=unique(nc$row_id)

##pattern
df1 <- data.frame(
  x    = rep(1:6, 9),
  y    = rep(1:9, each=6),
  name = gridpattern::names_magick,
  stringsAsFactors = FALSE
)

df1<-df1%>%mutate(row_id=row_number())



df_color<-data.frame()

pattern_rand_df_final<-data.frame()


p1 <- ggplot()

ids=1:10

for(id in ids){
  df <- nc%>%filter(id==row_id)
  x=paste(sample(0:255,size=1,replace=TRUE),collapse=" ")
  y=paste(sample(0:255,size=1,replace=TRUE),collapse=" ")
  z=paste(sample(0:255,size=1,replace=TRUE),collapse=" ")
  
  zz=rgb(x,y,z, maxColorValue = 255)
  df_color<<-rbind(df_color,zz)
  df_color=df_color%>%mutate(row_id=row_number())
  df_color_f<-  df_color%>%filter(row_id==id)
  colnames(df_color_f)[1]='fill_color'
    
  num_rand=sample(1:54,1)
  pattern_rand_df_final<<-rbind(pattern_rand_df_final,num_rand)
  pattern_rand_df_final=pattern_rand_df_final%>%mutate(row_id=row_number())
  pattern_rand_df_final_filter<-  pattern_rand_df_final%>%filter(row_id==id)
  colnames(pattern_rand_df_final_filter)[1]='random_pattern'
  
  df1_f<-df1%>%filter(row_id==pattern_rand_df_final_filter$random_pattern)


  
p1<-p1 +  geom_sf_pattern(data = df, fill=df_color_f$fill_color, color = "black",pattern='magick',
                          pattern_type = I(df1_f$name))


}

##this creates the map 
p1

legend_df<-full_join(df_color,pattern_rand_df_final)

colnames(legend_df)[1]='color_fill'
colnames(legend_df)[3]='hex_fill_number_id'


legend_df<-left_join(legend_df,df1%>%select(name,row_id),by=c("hex_fill_number_id"="row_id"))

###this is the legend information i would like to add using cowplot 
legend_df<-left_join(legend_df,st_drop_geometry(nc)%>%select(row_id,NAME)%>%rename(county=NAME))