Merge pull request #201 from JosephBARBIERDARNAL/rayshader

Rayshader

.gitignore

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 **/.DS_Store
 .DS_Store
+*_cache/
+*.tif

410-map-2d-with-rayshader.Rmd

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+---
+title: "2d maps with rayshader"
+descriptionMeta: "This post explains how to build and customize 2d maps with the rayshader package. It provides reproducible code and explain how input data must be formatted."
+descriptionTop: "This post thoroughly details the process of building and customizing **2D maps** using the [rayshader](package/rayshader.html) package. It includes step-by-step, reproducible code examples and clearly explains the required formatting for input data.<br><br>By following this guide, you will learn how to create **visually appealing maps** and tailor them to meet your specific needs, ensuring your data is presented in the most effective way possible. Additionally, the post covers various customization options within **rayshader**, enabling you to enhance your maps with different visual **styles and effects**."
+sectionText: "Map section"
+sectionLink: "map.html"
+DataToVizText: "Data to Viz"
+DataToVizLink: "data-to-viz.com/graph/map.html"
+url: "410-map-2d-with-rayshader"
+output:
+  html_document:
+      self_contained: false    
+      mathjax: default
+      lib_dir: libs
+      template: template_rgg.html
+      css: style.css
+      toc: TRUE
+      toc_float: TRUE
+      toc_depth: 2
+      df_print: "paged"
+---
+
+
+```{r global options, include = FALSE}
+knitr::opts_chunk$set(warning=FALSE, message=FALSE, fig.align='center')
+```
+
+<div class="container">
+
+
+# Libraries
+***
+
+The [rayshader package](package/rayshader.html) makes it **simple** to create **shaded 2D relief maps**.
+
+Since the package is on **CRAN**, you can **install it** with `install.packages("rayshader")`.
+
+We also load the **`raster` package** to **access data** to work with.
+
+```{r}
+# install.packages("rayshader")
+library(rayshader)
+library(raster)
+```
+
+
+# Data format
+***
+
+The [rayshader](package/rayshader.html) package requires input data in an **elevation matrix format**. This is a specific matrix where each cell holds the **elevation value** for the corresponding map point.
+
+Here's how to obtain the **elevation matrix** of the **Grand Canyon** from a raster file using the `raster` package.
+
+```{r}
+# Define a region for the SRTM data (example: Grand Canyon)
+extent_gc <- extent(-113.0, -112.0, 36.0, 37.0)
+srtm_gc <- getData("SRTM", lon = -112.5, lat = 36.5)
+srtm_gc_cropped <- crop(srtm_gc, extent_gc)
+
+# Convert the raster data to matrix
+elevation_matrix <- raster_to_matrix(srtm_gc_cropped)
+```
+
+
+# Basic 2D map
+***
+
+Let's see how to create a basic 2D map with [rayshader](package/rayshader.html).
+
+We use the `sphere_shade()` function to create the map. It takes the **elevation matrix** as input and returns a shaded map, and then plot it with the `plot_map()` function.
+
+```{r}
+elevation_matrix %>%
+  sphere_shade(texture="desert", sunangle = 45) %>%
+  plot_map()
+```
+
+
+# Change texture
+***
+
+[rayshader](package/rayshader.html) includes a **specialized function** to create textures: `create_texture()`. This function accepts **5 colors as input** and generates a texture suitable for use in the `sphere_shade()` function.
+
+```{r}
+custom_texture <- create_texture("#fff673","#55967a","#8fb28a","#55967a","#cfe0a9")
+
+elevation_matrix %>%
+  sphere_shade(texture=custom_texture, sunangle = 45) %>%
+  plot_map()
+```
+
+# Change shade properties
+***
+
+The `add_shadow()` function can be used to add a shadow to the map. The `ray_shade()` function creates a shadow based on the sun angle, while the `ambient_shade()` function creates a shadow based on the ambient light.
+
+```{r, cache=TRUE}
+elevation_matrix %>%
+  sphere_shade(texture="desert", sunangle = 45, zscale = 50) %>%
+  add_shadow(ray_shade(elevation_matrix), 0.5) %>%  # Adds a ray-traced shadow
+  add_shadow(ambient_shade(elevation_matrix), 0) %>%  # Adds an ambient shadow
+  plot_map()
+```
+
+
+
+# Going further
+***
+
+You might be interested in
+
+- creating [3d maps with rayshader](411-map-3d-with-rayshader.html)
+- learning more about [rayshader with more examples](package/rayshader.html)
+
+
+
+<!-- Close container -->
+</div>
+
+
+
+
+```{r, echo=FALSE}
+htmltools::includeHTML("htmlChunkRelatedMap.html")
+```