Strange formatting of legend in ggplotly in R

Question

I\'m trying to turn a ggplot into a plotly. The ggplot renders fine, but when I put it through ggplotly, suddenly the legend adds parenthesis and \",1\" after the label.

Answer 1

Here's yet another elegant solution. Under the hood it detects if a plotly legend name option is available and if so, removes the "(" and ",1)".

library(ggplot2)
library(plotly)
library(stringr)
library(dplyr)

data = data.frame(Date=as.Date(c("2017-09-12","2017-10-15")), PubB4=c(2,3), category=c("Foo", "Bar"))

myplot = ggplotly(ggplot(data, aes(x=Date, y=PubB4))+
    geom_hline(aes(yintercept=2.5, color="my line label"))+
    geom_point(aes(fill=category), size=4))

for (i in 1:length(myplot$x$data)){
    if (!is.null(myplot$x$data[[i]]$name)){
        myplot$x$data[[i]]$name =  gsub("\\(","",str_split(myplot$x$data[[i]]$name,",")[[1]][1])
    }
}

myplot

Answer 2

Since nothing I did worked, I took the dive and taught myself how to create the chart directly in plotly. For the benefit of possible future viewers, here's how the chart is recreated in plotly (sans some beautification that I'll get around to another time):

plot_ly(sorted, x=~CommDate) %>%
  add_markers(y=~PubB4, color=~factor(CommName), size=I(15)) %>% 
  add_lines(x=loess.smooth(sorted$CommDate,sorted$PubB4)$x,         
    y=loess.smooth(sorted$CommDate,sorted$PubB4)$y, name = "Rolling Average", 
    showlegend = TRUE, size=I(3)) %>%
  add_lines(x=c(min(sorted$CommDate),max(sorted$CommDate)),y=4, 
    color=I("red"), name="target", size=I(3)) %>%
  layout(yaxis=(list(range=c(0,max(c(4.5,sorted$PubB4))))),xaxis=list(range=c(min(sorted$CommDate)-10, max(sorted$CommDate)+5))) 

Answer 3

Here's an approach that worked for me. It involves diving into the resulting plotly object and cleaning up the legend names.

The first part creates a function to detect if the plotly list element has a legend specified and then cleans it up.

clean_plotly_leg <- function(.plotly_x, .extract_str) {
  # Inpects an x$data list in a plotly object, cleans up legend values where appropriate
  if ("legendgroup" %in% names(.plotly_x)) {
    # The list includes a legend group

    .plotly_x$legendgroup <- stringr::str_extract(.plotly_x$legendgroup, .extract_str)
    .plotly_x$name <- stringr::str_extract(.plotly_x$name, .extract_str)

  }
  .plotly_x


}

The second part applies it to your example, but with an intermediate step.

sorted_plotly <-
  ggplotly(ggplot(sorted1, aes(x=as.Date(CommDate), y=PubB4))+
           geom_smooth(level=0.0, aes(colour="Moving average"), se=FALSE)+
           geom_point(aes(fill=CommName), size=4)+
           expand_limits(y=c(0,4.5))+
           geom_line(mapping=aes(y=4),colour="orangered3",size=1)+
           geom_text(mapping=aes(y=4.2, x=min(sorted1$CommDate)+4), label="Target", size=3)+
           xlab("Committee Date")+
           guides(fill=guide_legend(title="Committee Names"), colour=guide_legend(title.theme=element_blank(),title=NULL))+
           scale_x_date(labels = date_format("%b-%y"))+
           theme_light()+
           theme(plot.title=element_text(hjust=0.5, size=12),panel.grid.major.x = (element_blank()), 
                 panel.grid.minor.x = (element_blank()), 
                 axis.title = element_text(size=8), legend.title = element_text(size=10),
                 legend.text = element_text(size=8), legend.box = 'vertical', legend.spacing.y = unit(-2,"mm"))+
           scale_colour_manual(name="",values="#0072B2"))

sorted_plotly$x$data <-
  sorted_plotly$x$data %>% 
  map(clean_plotly_leg, "[^\\(][^,]*") # ie remove the opening bracket, if one exists, and extract each character up to the first comma

sorted_plotly 

I'd welcome any suggestions for making this code more efficient, but at least it works

Answer 4

Here's a workaround that actually works:

# First, repeating your code, noting the plot as p1
# --------------------------------------------------
sorted1<-data.frame(CommDate=c(as.Date("2017-09-12"), as.Date("2017-10-15")), CommName=c("Foo", "Bar"), PubB4=c(2,3))
p1 <- ggplotly(ggplot(sorted1, aes(x=as.Date(CommDate), y=PubB4))+
           geom_smooth(level=0.0, aes(colour="Moving average"), se=FALSE)+
           geom_point(aes(fill=CommName), size=4)+
           expand_limits(y=c(0,4.5))+
           geom_line(mapping=aes(y=4),colour="orangered3",size=1)+
           geom_text(mapping=aes(y=4.2, x=min(sorted1$CommDate)+4), label="Target", size=3)+
           xlab("Committee Date")+
           guides(fill=guide_legend(title="Committee Names"), colour=guide_legend(title.theme=element_blank(),title=NULL))+
           scale_x_date(labels = date_format("%b-%y"))+
           theme_light()+
           theme(plot.title=element_text(hjust=0.5, size=12),panel.grid.major.x = (element_blank()), 
                 panel.grid.minor.x = (element_blank()), 
                 axis.title = element_text(size=8), legend.title = element_text(size=10),
                 legend.text = element_text(size=8), legend.box = 'vertical', legend.spacing.y = unit(-2,"mm"))+
           scale_colour_manual(name="",values="#0072B2"))

Now we can proceed to the workaround:

# Now, the workaround:
# ------------------------------------------------------
p1Names <- unique(sorted1$CommName) # we need to know the "true" legend values
for (i in 1:length(p1$x$data)) { # this goes over all places where legend values are stored
  n1 <- p1$x$data[[i]]$name # and this is how the value is stored in plotly
  n2 <- " "
  for (j in 1:length(p1Names)) {
    if (grepl(x = n1, pattern = p1Names[j])) {n2 = p1Names[j]} # if the plotly legend name contains the original value, replace it with the original value
  }
  p1$x$data[[i]]$name <- n2 # now is the time for actual replacement
  if (n2 == " ") {p1$x$data[[i]]$showlegend = FALSE}  # sometimes plotly adds to the legend values that we don't want, this is how to get rid of them, too
}
p1   # now we can see the result :-)