code_01.R

library(sf)

## Linking to GEOS 3.6.2, GDAL 2.2.3, PROJ 4.9.3

library(ggplot2)
library(dplyr)

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

setwd("~/Dropbox/BGU/1_Other/Siddhartha_Mandal/p_03_India_states_shapefile/")

# Read polygon Shapefile
dat = st_read("India_state_code.shp", stringsAsFactors = FALSE)

## Reading layer `India_state_code' from data source `/home/michael/Dropbox/BGU/1_Other/Siddhartha_Mandal/p_03_India_states_shapefile/India_state_code.shp' using driver `ESRI Shapefile'
## Simple feature collection with 36 features and 2 fields
## geometry type:  MULTIPOLYGON
## dimension:      XY
## bbox:           xmin: 68.18625 ymin: 6.755953 xmax: 97.41529 ymax: 37.07827
## epsg (SRID):    4326
## proj4string:    +proj=longlat +datum=WGS84 +no_defs

# Reshape polygon layer to table
pol = fortify(as(dat, "Spatial"), region = "ST_2code")
pol = rename(pol, ST_2code = id)
pol = left_join(pol, st_set_geometry(dat, NULL), "ST_2code")
head(pol)

##       long      lat order  hole piece ST_2code group
## 1 92.89898 12.91588     1 FALSE     1       AN  AN.1
## 2 92.89905 12.91512     2 FALSE     1       AN  AN.1
## 3 92.89905 12.91459     3 FALSE     1       AN  AN.1
## 4 92.89942 12.91456     4 FALSE     1       AN  AN.1
## 5 92.89948 12.91459     5 FALSE     1       AN  AN.1
## 6 92.89969 12.91499     6 FALSE     1       AN  AN.1
##                      ST_NM
## 1 Andaman & Nicobar Island
## 2 Andaman & Nicobar Island
## 3 Andaman & Nicobar Island
## 4 Andaman & Nicobar Island
## 5 Andaman & Nicobar Island
## 6 Andaman & Nicobar Island

# Plot with ggplot2
ggplot() + 
  geom_polygon(
    data = pol, 
    aes(x = long, y = lat, group = group, fill = ST_2code),
    alpha = 0.75
  )