---
title: "Adding_Basic_Map"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Adding_Basic_Map}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
```

```{r setup}
library(ggmapcn)
```

## Introduction

The ggmapcn package provides various tools for visualizing geographic data in China and beyond. This vignette demonstrates the basic and advanced usage of `geom_mapcn()` and `geom_world()` for plotting administrative boundaries and combining geographic data.

## Example 1: Basic Map of China

To plot a map of China with province boundaries, use the `geom_mapcn()` function. The map uses the Azimuthal Equal Distance projection by default.

```{r example1, fig.alt='Basic Map'}
ggplot() +
  geom_mapcn() +
  theme_minimal()
```

## Example 2: Adding Buffer Zones and Coastlines

Here’s a comprehensive example demonstrating how to plot province boundaries, buffer zones, and coastlines on the same map:

```{r example2, fig.alt='Map of China'}
ggplot() +
  geom_buffer_cn(mainland_dist = 40000) +
  geom_buffer_cn(mainland_dist = 20000, fill = "#BBB3D8") +
  geom_mapcn(fill = "white") +
  geom_boundary_cn() +
  theme_bw()
```

## Example 3: Overlaying China on a World Map

The `geom_world()` function allows you to visualize global data, while `geom_mapcn()` overlays China for detailed analysis.

```{r example3, fig.alt='Map of world'}
# Define projections
china_proj <- "+proj=aeqd +lat_0=35 +lon_0=105 +ellps=WGS84 +units=m +no_defs"

# Combine world map as a background and China map as overlay
ggplot() +
  # World map as background
  geom_world(fill = "gray90", color = "gray70", linewidth = 0.2) +
  coord_proj(
    crs = "+proj=merc",
    xlim = c(-180, 180),
    ylim = c(-90, 90)
  ) +
  # Overlay China map
  geom_mapcn(
    fill = "lightblue",
    color = "black",
    linewidth = 0.5
  ) +
  geom_boundary_cn(color = "red", linewidth = 0.6) +
  theme_minimal()
```

## Example 3: Filtering China and Its Neighbors

This example demonstrates filtering for China and its neighboring countries, highlighting China in red.

```{r example4, fig.alt='Map of China'}
# Define neighboring countries
china_neighbors <- c("CHN", "AFG", "BTN", "MMR", "LAO", "NPL", "PRK", "KOR",
                     "KAZ", "KGZ", "MNG", "IND", "BGD", "TJK", "PAK", "LKA", "VNM")

# Plot world map with filtered countries
ggplot() +
  geom_world(fill = "gray90", color = "gray70", linewidth = 0.2) +
  geom_world(
    filter = china_neighbors,
    filter_attribute = "SOC",
    fill = "lightblue",
    color = "black",
    linewidth = 0.5
  ) +
  geom_world(
    filter = "CHN",
    filter_attribute = "SOC",
    fill = "red",
    color = "black",
    linewidth = 0.8
  ) +
  coord_proj(
    crs = "+proj=merc",
    xlim = c(60, 140),
    ylim = c(-10, 60)
  ) +
  theme_minimal()
```
