Drawing point to another point in R?

Question

I have a information of migration data of different countries to Mexico. I want to represent it in a sanky. I am new to R and having a difficult time to produce it. Can someone please help me to achieve this? The destination is Mexico, so all the data flow will be to one point

df

Country         2013       2014       2015      2016       Dest
UK              1200       1200       1207      1400       Mexico
China           630        700        800       940        Mexico
Canada          1000       1000       950       920        Mexico
Brazil          820        670        550       230        Mexico
France          400        200        700       700        Mexico
Australia       440        350        340       780        Mexico

Sankey diagram example:

Asked By: ssdn

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Source

Answer 1

A different option could be using ggalluvial to create an alluvial workflow of the values per country over the years and the total per year. Here is a reproducible example:

# remotes::install_github("davidsjoberg/ggsankey")
library(ggalluvial)  
library(dplyr)
library(ggplot2)
library(tidyr)
library(scales)
df %>%
  pivot_longer(cols = -`Country`:`2016`) %>%
  mutate(value = as.numeric(gsub(",", "", value))) %>%
  ggplot(aes(x = name, y = value, alluvium = Country)) +
  geom_alluvium(aes(fill = Country, colour = Country),
                alpha = .75, decreasing = FALSE) +
  ggtitle("Migration to Mexico") +
  scale_y_continuous(breaks=pretty_breaks()) +
  theme_bw()

^{Created on 2022-09-04 with reprex v2.0.2}

Answered By: Quinten

Answer 2

With ggsankey::geom_sankey_bump:

#remotes::install_github("davidsjoberg/ggsankey")
library(ggsankey)

dat %>% 
  #data wrangling
  mutate(across(num_range("X", 2013:2016), ~ as.numeric(gsub(",", "", .x)))) %>% 
  pivot_longer(-c(Country, Dest), names_to = "year", names_prefix = "X", names_transform = as.numeric) %>% 
  
  #plot
  ggplot(aes(x = year, node = Country, fill = Country, value = value)) +
  geom_sankey_bump(space = 1, type = "alluvial", 
                   color = "transparent", alpha = 0.7) +
  scale_y_continuous(label = scales::comma) +
  theme_sankey_bump(base_size = 16) +
  theme(legend.position = "bottom")

Answered By: Maël

Answer 3

Here is a different way to visualise your data. We use plotly to create a dynamic animation of the flow of migrants into Mexico over time.

# Need to reshape data from wide to long and prepare data for plotly
data_long <- data %>%
    rename(source = Country, target = Dest) %>%
    pivot_longer(matches("\d{4}"), names_to = "year") %>%
    pivot_longer(c(source, target), values_to = "country") %>%
    mutate(node_id = as.factor(country))

# Plotly Sankey diagrams need a link list that gives 0-based indices 
# (instead of node names)
link_list <- data_long %>% 
    select(-country) %>%
    mutate(node_id = as.integer(node_id) - 1) %>%
    pivot_wider(names_from = "name", values_from = "node_id") %>%
    arrange(year) %>%
    as.list()
    
# Now we're ready to plot
library(plotly)
plot_ly(
    type = "sankey",
    orientation = "h",
    node = list(
        label = levels(data_long$node_id),
        pad = 15,
        thickness = 20),
    link = link_list,
    frame = ~link_list$year) %>%
    animation_slider(currentvalue = list(prefix = "Year: "))

Sample data

data <- read.table(text = "Country         2013       2014       2015      2016       Dest
UK              1200       1200       1207      1400       Mexico
China           630        700        800       940        Mexico
Canada          1000       1000       950       920        Mexico
Brazil          820        670        550       230        Mexico
France          400        200        700       700        Mexico
Australia       440        350        340       780        Mexico", header = TRUE, check.names = FALSE)

Answered By: Maurits Evers

Drawing point to another point in R?

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Sample data