Session 5 R practice, Exercise 3

Exercise 3: Using Plotly for maps

You will need plotly installed to run the code. If you do not have it installed, run install.packages("plotly").

Use knit to run this code.

# The file mg.csv contains the following information for Typhoon Mangkhut:
#     - lat: latitude
#     - lon: longitude (fixed)
#     - dt: Date time in format "%Y%b%d %H%M%S"
mg <- read.csv("mg.csv")

# Sample of the data:
mg[1:5,]

##   X.1  X               dt   lat    lon
## 1  59 59 2018SEP07 060000 12.10 166.20
## 2  60 60 2018SEP07 063000 12.03 166.16
## 3  61 61 2018SEP07 070000 11.98 166.11
## 4  62 62 2018SEP07 073000 11.95 166.04
## 5  63 63 2018SEP07 080000 11.94 165.96

# Load plotly for plotting
library(plotly)

## Warning: package 'plotly' was built under R version 3.5.1

## Loading required package: ggplot2

## Warning: package 'ggplot2' was built under R version 3.5.1

## 
## Attaching package: 'plotly'

## The following object is masked from 'package:ggplot2':
## 
##     last_plot

## The following object is masked from 'package:stats':
## 
##     filter

## The following object is masked from 'package:graphics':
## 
##     layout

# Settings for the plot -- complete, but some other options are listed in the comments
geo <- list(
  showland = TRUE,
  showlakes = TRUE,
  showcountries = TRUE,
  showocean = TRUE,
  countrywidth = 0.5,
  landcolor = toRGB("grey90"),  # Run colors() after loading plotly to see available colors
  lakecolor = toRGB("aliceblue"),
  oceancolor = toRGB("aliceblue"),
  projection = list(
    type = 'orthographic',  # Consider trying 'equirectangular' or 'steriographic'
    rotation = list(
      lon = 100,  # This sets the center longitude
      lat = 1,    # This sets the center latitude
      roll = 0
    )
  ),
  lonaxis = list(
    showgrid = TRUE,
    gridcolor = toRGB("gray40"),
    gridwidth = 0.5
  ),
  lataxis = list(
    showgrid = TRUE,
    gridcolor = toRGB("gray40"),
    gridwidth = 0.5
  )
)


# Plot
plot_geo() %>%
  add_markers(data=mg,
              x = ~lon,
              y = ~lat,
              text=~paste("Time: ", dt)) %>%
  layout(showlegend = TRUE, geo = geo,
    title = 'Typhoon Mangkhut, through 2018 Sept 17')

## Warning: package 'bindrcpp' was built under R version 3.5.1