Using ggplot2, plot the spatial locations of the DBH measurements using decimal degrees

Question

I'm new to R and I'm having trouble plotting this information. I have to set the plot boundary to the following coordinates: xmin: -96.34018 ymin: 30.61613 xmax: -96.33954 ymax: 30.61701. Scale the size of the symbols representing the trees to the DBH of the tree.

Could someone please help me with this

Answer 1

I am also new to the spatial analyses but I played with the data.

Sample code:

library(readr)
library(ggplot2)  
library(dplyr)  
library(rgdal)  
library(raster)  
library(rworldmap) 

(with_world <- ggplot() +
    geom_polygon(data = world, 
                 aes(x = long, y = lat, group = group),
                 fill = NA, colour = "black") + 
    geom_point(data = df,  
               aes(y = Latitude_dd, x = Longitude_dd),colour = "blue", alpha = 0.5, size = 5) +
    coord_quickmap() +  
    theme_classic() +  
    xlab("Longitude") +
    ylab("Latitude") + 
    guides(colour=guide_legend(title="Coordinates")))

Plot:

Sample data:

df<-structure(list(Number = c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 
12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 
28, 29, 30), Latitude_dd = c(30.6153, 30.61518, 30.61506, 30.615, 
30.61504, 30.61523, 30.6153, 30.61531, 30.61543, 30.61537, 30.61531, 
30.61522, 30.61529, 30.61559, 30.61566, 30.61553, 30.61565, 30.61575, 
30.61582, 30.61598, 30.61531, 30.61531, 30.61535, 30.61522, 30.61514, 
30.61512, 30.61504, 30.61504, 30.61511, 30.61489), Longitude_dd = c(-96.34108, 
-96.34117, -96.34149, -96.34158, -96.34149, -96.34147, -96.34138, 
-96.34131, -96.34146, -96.34151, -96.34155, -96.34171, -96.34176, 
-96.34147, -96.3413, -96.34155, -96.34161, -96.34169, -96.34178, 
-96.34205, -96.34089, -96.34071, -96.34076, -96.34062, -96.34061, 
-96.3407, -96.34069, -96.34069, -96.34092, -96.34091), DBH_in = c(1.31, 
5.22, 1.42, 8.99, 1.19, 13.72, 5.41, 5.24, 5.69, 5.39, 4.81, 
4.49, 18.92, 11.06, 8.24, 8.28, 3.8, 2.32, 2.1, 3.07, 1.83, 3.99, 
5.89, 2.18, 4.73, 2.47, 0.6, 4.22, 2.86, 4.82), DBH_cm = c(3.33, 
13.26, 3.61, 22.83, 3.02, 34.85, 13.74, 13.34, 14.45, 13.69, 
12.22, 11.4, 48.06, 28.09, 20.92, 21.03, 9.65, 5.89, 5.33, 7.8, 
4.65, 10.13, 14.96, 5.54, 12.01, 6.27, 1.52, 10.72, 7.26, 12.24
), Notes = c("A", "A", "A", "A", "A", "A", "A", "A", "A", "A", 
"A", "B", "B", "B", "B", "B", "B", "B", "B", "B", "B", "B", "B", 
"B", "B", "C", "C", "C", "C", "C")), spec = structure(list(cols = list(
    Number = structure(list(), class = c("collector_double", 
    "collector")), Latitude_dd = structure(list(), class = c("collector_double", 
    "collector")), Longitude_dd = structure(list(), class = c("collector_double", 
    "collector")), DBH_in = structure(list(), class = c("collector_double", 
    "collector")), DBH_cm = structure(list(), class = c("collector_double", 
    "collector")), Notes = structure(list(), class = c("collector_character", 
    "collector"))), default = structure(list(), class = c("collector_guess", 
"collector")), delim = ","), class = "col_spec"), problems = <pointer: 0x029ed310>, row.names = c(NA, 
-30L), class = c("spec_tbl_df", "tbl_df", "tbl", "data.frame"
))