I have a custom simplified function lc to plot lc of data.

It makes a graph for every month selected in data. I use assign to dynamically assign each plot to a new object to be used later. I have a counter and paste0 function to help change the name using assign in the for loop.

library(dplyr)
library(ggplot2)
library(ecotox)
df <- ecotox::lamprey_tox
lc<- function(data, dose='dose', months=c(), month='month', total='total', response='response'){

  data <- data%>% filter(month %in% c(months))
  counter=0
  for (i in months){
    counter <- counter + 1
    a <- data[data$month %in% i,]
    print(a)
    lc <- LC_probit((response/ total) ~ log10(as.numeric(dose)), p = c(50, 90),
                    weights = total,
                    data =a)
    LC50 <- lc$dose[1] #strip lc50
    LC90 <- lc$dose[2] #strip lc90
    assign(paste0('p', counter), ggplot(data=a,aes(x=log10(as.numeric(dose)),y=(response/total)))+
             geom_point(size=4)+ 
             geom_smooth(method="glm", 
                         method.args=list(family=binomial(link="probit")), 
                         aes(weight=total),colour="blue",se=TRUE, level=0.95) +
             geom_segment(aes(x = log10(LC50), xend = log10(LC50), y=-Inf, yend=0.5), linetype='dashed', size=1) +
             geom_segment(aes(x = -Inf, xend = log10(LC50), y=0.5, yend=0.5), linetype='dashed', size=1) +
             geom_segment(aes(x = log10(LC90), xend = log10(LC90), y=-Inf, yend=0.9), linetype='dashed', size=1) +
             geom_segment(aes(x = -Inf, xend = log10(LC90), y=0.9, yend=0.9), linetype='dashed', size=1)) 
          


    
   print(p1) 
    
    
  }

}

However, the plot doesn’t seem to update correctly. And by printing inside the foor loop, it seems that when I use the counter with assign function, it changes the plot, but for some reason, leaves geom_segment alone? As you can see, the geom_segment and geom_smooth don’t line up like they should. However…

lc(df, months=c('May', 'June', 'August'))

output:

If I change counter to a not-dynamically changing name, like 1, it works:

assign(paste0('p', 1), ggplot(data=a,aes(x=log10(as.numeric(dose)),y=(response/total)))+ 

Why is this? Thank you for any advice!