ggplotly display ggplot choropleth map ugly - r

Question

I am trying to make my beautiful ggplot map interactive with a tooltip using ggplotly. But the map rendered with ggploty is not beautiful.
Here is a picture of my map with only ggplot:
Here is a picture of my map when using ggplotly. It removes the legend and make the map ugly:
Is there another way of making my ggplot map interactive with a tooltip? And also ggplotly takes some time to render the interactive map:
Here is my sample code for my ggplot:
ggplot(data = sdpf_f, aes( fill = n,x = long, y = lat, group = group, text = tooltip)) +
geom_polygon(color = "white") +
theme_void() +
scale_fill_continuous(low="#c3ffff", high="#0291da",
guide = guide_legend(title.position = "top", label.position = "bottom", keywidth = 2,
keyheight = 0.5,
title = "Number of agreements"),na.value="lightgrey"
) +
theme(legend.position="bottom") +
coord_map()
Thanks & kind regards,
Akshay

Answer 1

I don't have your data and this isn't exactly the same, but it's fairly close to what I think you're expecting.
The libraries:
I called tidyverse for the plotting and piping. I called maps for the data I used and plotly for the Plotly graph.
I used a function that is derived from one of the ways ggplot sets the aspect ratio. I know I found this function on SO, but I don't remember who wrote it.
library(tidyverse)
library(maps)
library(plotly)
map_aspect = function(x, y) {
x.center <- sum(range(x)) / 2
y.center <- sum(range(y)) / 2
x.dist <- ggplot2:::dist_central_angle(x.center + c(-0.5, 0.5), rep(y.center, 2))
y.dist <- ggplot2:::dist_central_angle(rep(x.center, 2), y.center + c(-0.5, 0.5))
y.dist / x.dist
}
I had to create data as your question is not reproducible. I figured I would include it, so that my answer was reproducible.
ms <- map_data("state") %>%
mutate(n = ifelse(str_detect(region, "^a"), 1.0,
ifelse(str_detect(region, "^o"), 1.5,
ifelse(str_detect(region, "^t"), 2.0,
ifelse(str_detect(region, "^s"), 2.5,
ifelse(str_detect(region, "^w"),
3.0,
NA))))))
I modified your ggplot call. The only change is coord_fixed instead of coord_map. I did this so that Plotly could interpret the aspect ratio correctly. Within coord_fixed, I used the function map_aspect.
gp <- ggplot(data = ms, aes(fill = n, x = long, y = lat,
group = group, text = tooltip)) +
geom_polygon(color = "white") +
theme_void() +
scale_fill_continuous(low="#c3ffff", high="#0291da",
guide = guide_legend(title.position = "top",
label.position = "bottom",
keywidth = 2,
keyheight = 0.5,
title = "Number of agreements"),
na.value="lightgrey"
) +
theme(legend.position="bottom") +
coord_fixed(with(ms, map_aspect(long, lat)))
Then I created a Plotly object. I set some requirements for the layout, as well (horizontal legend at the bottom, with the legend title above the elements—similar to the legend in your ggplot call).
pp <- ggplotly(gp) %>%
layout(legend = list(orientation = "h", valign = "bottom",
title = list(side = "top"),
x = .02),
xaxis = list(showgrid = F), yaxis = list(showgrid = F),
showlegend = T)
Next, I needed to add the information for the legend. I chose to name the traces (which are split by color). I started by creating a vector of the names of the traces (which is what you see in the legend). I added a "" at the end, so that the NA-colored states wouldn't have a named trace (so they won't show in the legend).
This is likely something you'll need to change for your data.**
# the color values and the last one, which is for NAs, no legend
nm <- seq(1, 3, by = .5) %>% sprintf(fmt = "%.1f") %>% append(., "")
Then I wanted to ensure that showlegend was true for all but the NA (light gray) states. I created a vector of T and F.
legs <- c(rep(TRUE, 5), FALSE)
Then I added these to the plot.
invisible(lapply(1:length(pp$x$data),
function(i){
pp$x$data[[i]]$name <<- nm[i]
pp$x$data[[i]]$showlegend <<- legs[i]
}))