Chapter 2 Import libraries and sample dataset

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We will begin by loading necessary libraries. The sample dataset for this excercise can be downloaded manually from GitHub by accessing https://github.com/Vinit-Sehgal/SampleData

Alternatively, use the following code to download and extract the sample data from GitHub repository.

Install all necessary packages (Run once).

###############################################################
#~~~ Load required libraries
lib_names=c("terra", "tidyterra", "cetcolor", "scico", "tmap",    
            "gifski", "lubridate", #"Rcpp", 
            "raster","ggplot2","unikn","mapview",
            "gridExtra","rgdal","fields",
            "RColorBrewer","ncdf4","rasterVis",
            "rcartocolor","pacman","purrr","moments","tictoc", 
            "sf", "sp", "exactextractr","readxl", 
            "snow","future.apply","parallel")

# Load necessary packages
invisible(suppressMessages
          (suppressWarnings
            (lapply
              (lib_names, require, character.only = T))))

# An easy way to load multiple packages is through pacman::p_load
# pacman::p_load("raster","ggplot2","unikn","mapview",
#             "gridExtra","rgdal","fields",
#             "RColorBrewer","ncdf4","rasterVis", "moments", "tictoc", "tibble")

# Update packages if they are already installed
# update.package(ask = FALSE)

Note: The legacy R spatial infrastructure packages - maptools, rgdal and rgeos have been archived by CRAN from October 16, 2023; these retired packages will continue to be available as source packages on https://cran.r-project.org/src/contrib/Archive but won’t undergo any further development.
We will now download the workshop repository, which contains all data we will use for this exercise.

###############################################################
#~~~ Import sample data from GitHub repository
download.file(url = "https://github.com/Vinit-Sehgal/SampleData/archive/master.zip",
destfile = "SampleData-master.zip")    # Download ".Zip"

# Unzip the downloaded .zip file
unzip(zipfile = "SampleData-master.zip")
# getwd()                           # Current working directory
list.files("./SampleData-master")   # List folder contents

##  [1] "CMIP_land"                               
##  [2] "functions"                               
##  [3] "images"                                  
##  [4] "Largescale_geospatial_analysis_2022.html"
##  [5] "Largescale_geospatial_analysis_2023.html"
##  [6] "location_points.xlsx"                    
##  [7] "ne_10m_coastline"                        
##  [8] "raster_files"                            
##  [9] "README.md"                               
## [10] "sample_pdfs"                             
## [11] "SMAP_L3_USA.nc"                          
## [12] "SMAPL4_H5"                               
## [13] "SMAPL4_rasters"                          
## [14] "SMOS_nc"                                 
## [15] "USA_states"                              
## [16] "Workbook_DVGAR21-Part1.html"             
## [17] "Workbook_DVGAR21-Part2.html"

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