vignettes/hurricane-info.knit.md
In fmax85/hurricane: Storm observations geom
title: "hurricane package"
author: "F. Max"
date: "2018-05-02"
output:
html_document:
df_print: tibble
keep_md: yes
vignette: >
%\VignetteIndexEntry{hurricane package}
%\VignetteEncoding{UTF-8}
%\VignetteEngine{knitr::rmarkdown}
The rationale of this package is to grant peer-grading for the Coursera course of Building Data Visualization Tools. As a potentially useful byproduct, the code in this package contains a customized stat/geom pair named *_hurricane that can be used to visualize storm observation data. Particularly, provided data are arranged in an appropriate way, this geom draws the regions of a storm observation corresponding to the same wind speed level, for the four quadrants defined by an origin point. The contour of the "iso-speed" levels are connected by a polygon grid object.
Introduction
The storm observation data that can be fed to *_hurricane functions are based on the dataset available at Tropical cyclone EBTD. An R script describing the required data frame generating process is provided in the package.
Package content
The package contains the following files and folders:
- R -- includes the R scripts of the
{stat/geom}_hurricane functions
- man -- includes the documentation of the
{stat/geom}_hurricane functions, as well as the ike dataset provided along with the package
- data -- includes the
ike dataset, generated by the data_cleaner.R script
- resource -- includes the data_cleaner.R script used to generate the appropriate data frame for the
{stat/geom}_hurricane functions, as well as the make_figure.R script adopted to produce the Figure below
- vignettes -- includes this vignette
- figures -- includes the picture shown below, generated using the
geom_hurricane function in the make_figure.R script
- NAMESPACE -- NAMESPACE file for this package
- DESCRIPTION -- package descritpion file
- ike-13sep.png -- picture (same as below) generated using the
geom_hurricane function
Ike storm observation with geom_hurricane. Data recorded at 06:00 of 13-Sep, 2008.
Code & Data
The reference data of the tropical cyclons is provided in the EBTD database. The ike data frame constitutes a subset of the aforementioned database and is provided along with this package. The format of the data frame is different from the raw data and is strictly required by the {stat/geom}_hurricane functions. For convenience the ike data frame is shown below:
#> # A tibble: 174 x 9
#> storm_id date latitude longitude wind_speed ne nw se sw
#> <chr> <chr> <dbl> <dbl> <chr> <int> <int> <int> <int>
#> 1 Ike-2008 2008-09… 17.2 -37.0 34 0 0 0 0
#> 2 Ike-2008 2008-09… 17.2 -37.0 50 0 0 0 0
#> 3 Ike-2008 2008-09… 17.2 -37.0 64 0 0 0 0
#> 4 Ike-2008 2008-09… 17.3 -38.4 34 120 60 75 0
#> 5 Ike-2008 2008-09… 17.3 -38.4 50 0 0 0 0
#> 6 Ike-2008 2008-09… 17.3 -38.4 64 0 0 0 0
#> 7 Ike-2008 2008-09… 17.5 -39.9 34 130 75 110 0
#> 8 Ike-2008 2008-09… 17.5 -39.9 50 0 0 0 0
#> 9 Ike-2008 2008-09… 17.5 -39.9 64 0 0 0 0
#> 10 Ike-2008 2008-09… 17.8 -41.3 34 140 90 120 0
#> # ... with 164 more rows
The ike data frame is generated with the following code (see the data_cleaner.R script, in the resource folder):
# Load and tidy ebrtk data
#
library(magrittr)
library(dplyr)
library(readr)
library(tidyr)
library(stringr)
library(lubridate)
#
# read source data
ext_tracks_widths <- c(7, 10, 2, 2, 3, 5, 5, 6, 4, 5, 4, 4, 5, 3, 4, 3, 3, 3,
4, 3, 3, 3, 4, 3, 3, 3, 2, 6, 1)
ext_tracks_colnames <- c("storm_id", "storm_name", "month", "day",
"hour", "year", "latitude", "longitude",
"max_wind", "min_pressure", "rad_max_wind",
"eye_diameter", "pressure_1", "pressure_2",
paste("radius_34", c("ne", "se", "sw", "nw"), sep = "_"),
paste("radius_50", c("ne", "se", "sw", "nw"), sep = "_"),
paste("radius_64", c("ne", "se", "sw", "nw"), sep = "_"),
"storm_type", "distance_to_land", "final")
ext_tracks <- read_fwf("ebtrk_atlc_1988_2015.txt",
fwf_widths(ext_tracks_widths, ext_tracks_colnames),
na = "-99")
#
# refactor quadrant radii
features <- c("storm_name", "year", "month", "day", "hour", "latitude", "longitude")
tmp <- ext_tracks %>% select(features, starts_with("radius_")) %>%
filter(storm_name == "IKE") %>%
gather(key, value, -features) %>%
extract(key, c("wind_speed", "quadrant"), "(\\d+)_(..)") %>%
spread(quadrant, value)
#
# add (remove) new (old) features
ike <- tmp %>% mutate(date = as.character(make_datetime(as.integer(year), as.integer(month),
as.integer(day), as.integer(hour)))) %>%
mutate(longitude = -longitude) %>%
mutate(storm_id = paste(str_to_title(storm_name), year, sep = "-")) %>%
select(storm_id, date, latitude, longitude, wind_speed, ne, nw, se, sw)
The stat_hurricane function builds the points, which form the contours of the wind radii, by means of the \link[geosphere]{destPoint} function. geom_hurricane inherits from geom_polygon. The default geom associated to stat_hurricane is geom_hurricane, as shown by the following code chunk:
library(ggplot2)
ike_1 <- ike %>% dplyr::filter(latitude > 29 & latitude < 30)
ggplot(data = ike_1, mapping = aes(x = longitude, y = latitude)) +
stat_hurricane(mapping = aes(x = longitude, y = latitude, r_ne = ne, r_se = se, r_sw = sw,
r_nw = nw, colour = wind_speed), alpha = 0) +
theme_minimal()
Simple usage of stat_hurricane
Warning
When adding a geom_hurricane layer on top of a map object, as in the first figure, the boundaries of the latitude and longitude of the complete picture map is determined by the map object. In this case, if any points of the wind radii computed by geom_hurricane exceed those limits, the resulting plot will be incorrect. It is advised to use the scale_radii aestethic to reduce the size of the geom_hurricane polygons or to use a less zoomed-in map object.
References
- R.D. Peng, S. Kross, and B. Anderson, “Mastering Software Development in R”, section 4.7: Building New Graphical Elements
- Documentation of the
ggplot2::geom_polygon function, version 2.2.1.9000
- Vignette from the
ggplot2 package, Extending ggplot2
- Vignette from the
geosphere package, Introduction to the geosphere package
fmax85/hurricane documentation built on May 28, 2019, 2:31 a.m.
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
title: "hurricane package" author: "F. Max" date: "2018-05-02" output: html_document: df_print: tibble keep_md: yes vignette: > %\VignetteIndexEntry{hurricane package} %\VignetteEncoding{UTF-8} %\VignetteEngine{knitr::rmarkdown}
The rationale of this package is to grant peer-grading for the Coursera course of Building Data Visualization Tools. As a potentially useful byproduct, the code in this package contains a customized stat/geom pair named *_hurricane that can be used to visualize storm observation data. Particularly, provided data are arranged in an appropriate way, this geom draws the regions of a storm observation corresponding to the same wind speed level, for the four quadrants defined by an origin point. The contour of the "iso-speed" levels are connected by a polygon grid object.
Introduction
The storm observation data that can be fed to *_hurricane functions are based on the dataset available at Tropical cyclone EBTD. An R script describing the required data frame generating process is provided in the package.
Package content
The package contains the following files and folders:
- R -- includes the R scripts of the
{stat/geom}_hurricanefunctions - man -- includes the documentation of the
{stat/geom}_hurricanefunctions, as well as theikedataset provided along with the package - data -- includes the
ikedataset, generated by the data_cleaner.R script - resource -- includes the data_cleaner.R script used to generate the appropriate data frame for the
{stat/geom}_hurricanefunctions, as well as the make_figure.R script adopted to produce the Figure below - vignettes -- includes this vignette
- figures -- includes the picture shown below, generated using the
geom_hurricanefunction in the make_figure.R script - NAMESPACE -- NAMESPACE file for this package
- DESCRIPTION -- package descritpion file
- ike-13sep.png -- picture (same as below) generated using the
geom_hurricanefunction
Ike storm observation with geom_hurricane. Data recorded at 06:00 of 13-Sep, 2008.
Code & Data
The reference data of the tropical cyclons is provided in the EBTD database. The ike data frame constitutes a subset of the aforementioned database and is provided along with this package. The format of the data frame is different from the raw data and is strictly required by the {stat/geom}_hurricane functions. For convenience the ike data frame is shown below:
#> # A tibble: 174 x 9
#> storm_id date latitude longitude wind_speed ne nw se sw
#> <chr> <chr> <dbl> <dbl> <chr> <int> <int> <int> <int>
#> 1 Ike-2008 2008-09… 17.2 -37.0 34 0 0 0 0
#> 2 Ike-2008 2008-09… 17.2 -37.0 50 0 0 0 0
#> 3 Ike-2008 2008-09… 17.2 -37.0 64 0 0 0 0
#> 4 Ike-2008 2008-09… 17.3 -38.4 34 120 60 75 0
#> 5 Ike-2008 2008-09… 17.3 -38.4 50 0 0 0 0
#> 6 Ike-2008 2008-09… 17.3 -38.4 64 0 0 0 0
#> 7 Ike-2008 2008-09… 17.5 -39.9 34 130 75 110 0
#> 8 Ike-2008 2008-09… 17.5 -39.9 50 0 0 0 0
#> 9 Ike-2008 2008-09… 17.5 -39.9 64 0 0 0 0
#> 10 Ike-2008 2008-09… 17.8 -41.3 34 140 90 120 0
#> # ... with 164 more rows
The ike data frame is generated with the following code (see the data_cleaner.R script, in the resource folder):
# Load and tidy ebrtk data
#
library(magrittr)
library(dplyr)
library(readr)
library(tidyr)
library(stringr)
library(lubridate)
#
# read source data
ext_tracks_widths <- c(7, 10, 2, 2, 3, 5, 5, 6, 4, 5, 4, 4, 5, 3, 4, 3, 3, 3,
4, 3, 3, 3, 4, 3, 3, 3, 2, 6, 1)
ext_tracks_colnames <- c("storm_id", "storm_name", "month", "day",
"hour", "year", "latitude", "longitude",
"max_wind", "min_pressure", "rad_max_wind",
"eye_diameter", "pressure_1", "pressure_2",
paste("radius_34", c("ne", "se", "sw", "nw"), sep = "_"),
paste("radius_50", c("ne", "se", "sw", "nw"), sep = "_"),
paste("radius_64", c("ne", "se", "sw", "nw"), sep = "_"),
"storm_type", "distance_to_land", "final")
ext_tracks <- read_fwf("ebtrk_atlc_1988_2015.txt",
fwf_widths(ext_tracks_widths, ext_tracks_colnames),
na = "-99")
#
# refactor quadrant radii
features <- c("storm_name", "year", "month", "day", "hour", "latitude", "longitude")
tmp <- ext_tracks %>% select(features, starts_with("radius_")) %>%
filter(storm_name == "IKE") %>%
gather(key, value, -features) %>%
extract(key, c("wind_speed", "quadrant"), "(\\d+)_(..)") %>%
spread(quadrant, value)
#
# add (remove) new (old) features
ike <- tmp %>% mutate(date = as.character(make_datetime(as.integer(year), as.integer(month),
as.integer(day), as.integer(hour)))) %>%
mutate(longitude = -longitude) %>%
mutate(storm_id = paste(str_to_title(storm_name), year, sep = "-")) %>%
select(storm_id, date, latitude, longitude, wind_speed, ne, nw, se, sw)
The stat_hurricane function builds the points, which form the contours of the wind radii, by means of the \link[geosphere]{destPoint} function. geom_hurricane inherits from geom_polygon. The default geom associated to stat_hurricane is geom_hurricane, as shown by the following code chunk:
library(ggplot2)
ike_1 <- ike %>% dplyr::filter(latitude > 29 & latitude < 30)
ggplot(data = ike_1, mapping = aes(x = longitude, y = latitude)) +
stat_hurricane(mapping = aes(x = longitude, y = latitude, r_ne = ne, r_se = se, r_sw = sw,
r_nw = nw, colour = wind_speed), alpha = 0) +
theme_minimal()
Simple usage of stat_hurricane
Warning
When adding a geom_hurricane layer on top of a map object, as in the first figure, the boundaries of the latitude and longitude of the complete picture map is determined by the map object. In this case, if any points of the wind radii computed by geom_hurricane exceed those limits, the resulting plot will be incorrect. It is advised to use the scale_radii aestethic to reduce the size of the geom_hurricane polygons or to use a less zoomed-in map object.
References
- R.D. Peng, S. Kross, and B. Anderson, “Mastering Software Development in R”, section 4.7: Building New Graphical Elements
- Documentation of the
ggplot2::geom_polygonfunction, version 2.2.1.9000 - Vignette from the
ggplot2package, Extending ggplot2 - Vignette from the
geospherepackage, Introduction to the geosphere package
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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