In rsizem2/wind-radii-geom: Defines Geom For Plotting Wind Fields

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.path = "man/figures/README-",
  out.width = "100%"
)

The package includes a custom ggplot geom for visualizing directional wind fields in the four quadrants defined by the cardinal directions (e.g. NE, NW, SW, SE).

Installation

You can install this package directly from github using the devtools package:

``` {r, eval = FALSE} library(devtools) install_github("rsizem2/wind-radii-geom")

## Example

We include a raw dataset which can be used with our new geom. To access this data, use the `get_hurricane_data` function, which will return the data in a format that can be most easily fed into our new geom. We restrict our attention to a specific observation corresponding to Hurricane Ike at 6:00 UTC on September 13, 2008, when the hurricane was just off the Texas coast.

```r
library(hurricane)
library(tidyverse)
library(lubridate)
library(maps)

ike_data <- get_hurricane_data() %>%
    dplyr::filter(startsWith(storm_id, "IKE"),
           datetime %in% lubridate::ymd_hm("2008-09-13 06:00"))

We use the maps package to load map data for more context for our visualizations, which will be used as the baseplot on which we'll add our new geom as a layer. For the sake of our visualization we grab data for Louisiana and Texas.

gulf_coast <- map_data("state") %>% subset(region %in% c('texas','louisiana'))

base_map <- ggplot(data = gulf_coast) + 
    geom_polygon(aes(x = long, y = lat, group = group), fill = "white", color = "black") +
    coord_fixed(1.3) 

base_map

We can then use our geom_hurricane function to add a new layer to this base plot, using the windspeed columns to determine the colors of each circular quadrant:

base_map + geom_hurricane(data = ike_data,
                          aes(x = longitude, y = latitude,
                              r_ne = NE, r_se = SE, r_nw = NW,  r_sw = SW,
                              fill = windspeed, color = windspeed, scale_radii = 0.65)) +
    scale_color_manual(name = "Wind speed (kts)",
                       values = c("red", "orange", "yellow")) +
    scale_fill_manual(name = "Wind speed (kts)",
                      values = c("red", "orange", "yellow")) +
    labs(x = NULL, y = NULL)