Animate foreign exchange rate x outbound Chinese tourisism. #rstats #plotly

cot_animate.R

library(readxl)
library(tidyr)
library(ggplot2)
library(broom)
library(rvest)
library(plotly)


# Import data -------------------------------------------------------------

# read data
cot <- read_excel("~/Downloads/outbound_tourism_china.xlsx", skip = 5)
# mod columns name
colnames(cot) <- c("country", "series", 1995:2016, "pct_chg_16_15")

# Convert to tidy format
long <- cot %>% 
    filter(series == "TFR") %>% 
    select(-pct_chg_16_15, -series) %>% 
    gather(year, arrivals, -country)
long

# Top 10 most popular country in 2016
top10_2016 <- long %>% filter(year == 2016) %>% top_n(wt = arrivals, n = 10) %>% pull(country)
top10_2016

long <- long %>% filter(country %in% top10_2016) %>% 
    # special treatment for Hong Kong
    mutate(country = gsub(country, pattern = "\\,\\s?\\w*$", replacement = "") %>% toupper())
long$country %>% unique()


# Currency code refence ---------------------------------------------------

# Get currency codes from iban.com
xml <- read_html("https://www.iban.com/currency-codes.html")

# Download table and convert to tibble
codes <- xml %>% html_node(css = "table.ibanindex.tablesorter.currencycodes") %>% html_table()
colnames(codes) <- c("country_name", "currency_name", "currency_letter", "currency_code")

codes <- codes %>% 
    mutate(country_name = gsub(country_name, pattern = "\\s+\\(THE\\)", replacement = "")) %>% 
    as.tibble()
codes


# Custom function to return year average ----------------------------------

base = "http://www.x-rates.com/average/?amount=100&from=CNY"

get_year_average <- function(to_country, year){
    
    xml <- paste0(base, "&to=", to_country, "&year=", year) %>% read_html()
    avg <- xml %>% html_nodes(css = ".avgRate") %>% html_text() %>% as.numeric() %>% mean()
    if(!is.nan(avg)){
        avg
    }else{
        NA
    }
}

# Only keep interested country
codes <- codes %>% filter(country_name %in% long$country)
# Get codes
long <- long %>% right_join(codes %>% select(country_name, currency_letter), by = c("country" = "country_name"))
# Get yearly average 
long <- long %>% rowwise() %>% 
    filter(year >= 2008) %>% 
    mutate(avg = get_year_average(currency_letter, year))

# Cambodia KHR is not available from xrates.com
long <- long %>% filter(!is.na(avg))

# Add currency growth
long <- long %>% 
    ungroup() %>% 
    mutate(avg_g = (avg - lag(avg)) / lag(avg) + 1)

# Animation ---------------------------------------------------------------

t <- list(
    family = "sans serif",
    size = 11,
    color = toRGB("grey50"))

long %>% 
    filter(year > 2008) %>% 
    plot_ly(
        x = ~avg_g,
        y = ~arrivals,
        text = ~country,
        color = ~country,
        frame = ~year,
        type = "scatter",
        mode = "markers",
        marker = list(size = 15),
        showlegend = F
    ) %>% 
    add_text(textfont = t, textposition = "top right") %>% 
    layout(
        xaxis = list(
          range = c(0.5, 1.5),
          title = "CNY to Foreign Ex Ratio (Growth)"
        ),
        yaxis = list(
            type = "log",
            title = "Number of Arrivals (log)"
        )
    ) %>% 
    animation_opts(
        1000, easing = "elastic", redraw = F
    )