https://github.com/3wen/legendMap

North arrow and scale bar for ggplot2 graphics.
https://github.com/3wen/legendMap

Last synced: 3 months ago
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North arrow and scale bar for ggplot2 graphics.

• Host: GitHub
• URL: https://github.com/3wen/legendMap
• Owner: 3wen
• Created: 2016-05-23T12:13:51.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2016-05-23T12:15:05.000Z (over 8 years ago)
• Last Synced: 2024-05-21T02:55:39.469Z (6 months ago)
• Language: R
• Size: 3.91 KB
• Stars: 8
• Watchers: 4
• Forks: 0
• Open Issues: 2
• Metadata Files:
  • Readme: README.md

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README

        
legendMap

==============

Provides functions to add a North arrow and/or a scale bar to maps done using ggplot2.

# How to Install

```{r}

devtools::install_github("3wen/legendMap")

```

# Examples

```{r}

# United States map

usa_map <- map_data("state")

P <- ggplot() + geom_polygon(data = usa_map, aes(x = long, y = lat, group = group)) + coord_map()

# Let us add the scale bar (without the North arrow)

P + scale_bar(lon = -130, lat = 26, 

              distance_lon = 500, distance_lat = 100, distance_legend = 200, 

              dist_unit = "km", orientation = FALSE)

# With the North arrow

P <- P + scale_bar(lon = -130, lat = 26,

                   distance_lon = 500, distance_lat = 100,

                   distance_legend = 200, dist_unit = "km")

# Modifying the theme a bit

P + theme(panel.grid.minor = element_line(colour = NA), panel.grid.minor = element_line(colour = NA),

          panel.background = element_rect(fill = NA, colour = NA), axis.text.x = element_blank(),

          axis.text.y = element_blank(), axis.ticks.x = element_blank(),

          axis.ticks.y = element_blank(), axis.title = element_blank(),

          rect = element_blank(),

          plot.margin = unit(0 * c(-1.5, -1.5, -1.5, -1.5), "lines"))

# France map

france_map <- map_data("france")

P_fr <- ggplot() + geom_polygon(data = france_map, aes(x = long, y = lat, group = group)) + coord_map()

# Let us add the scale bar

P_fr <- P_fr + scale_bar(lon = -5, lat = 42.5, 

                         distance_lon = 100, distance_lat = 20, 

                         distance_legend = 40, dist_unit = "km", 

                         arrow_length = 100, arrow_distance = 60, arrow_north_size = 6)

# Modifying the theme a bit

P_fr + theme(panel.grid.minor = element_line(colour = NA), panel.grid.minor = element_line(colour = NA),

             panel.background = element_rect(fill = NA, colour = NA), axis.text.x = element_blank(),

             axis.text.y = element_blank(), axis.ticks.x = element_blank(),

             axis.ticks.y = element_blank(), axis.title = element_blank(),

             rect = element_blank(),

             plot.margin = unit(0 * c(-1.5, -1.5, -1.5, -1.5), "lines"))

```