7  2015 Tree Census

Alexander Liu

7.1 Introduction

library(tidyverse)
library(sf)
library(redav)

7.2 Data

7.2.1 Description

7.2.2 Missing Value Analysis

df <- read_csv("data/2015_Tree.rds", show_col_types = FALSE)
# head(df)

# filter only missing values to avoid cluttering
df_missing <- df %>%
  select(where(~ any(is.na(.))))

plot_missing(df_missing, percent = FALSE)

7.3 Results

df %>%
  count(spc_common, sort = TRUE) %>%
  head(15) %>%
  ggplot(aes(x = reorder(spc_common, n), y = n)) +
  geom_col() +
  coord_flip()

Error in `count()`:
! Must group by variables found in `.data`.
✖ Column `spc_common` is not found.

boroughs <- read_sf("data/nyc_boroughs/nybb.shp")

top9_species <- df %>%
  count(spc_common, sort = TRUE) %>%
  slice_head(n = 9) %>%
  pull(spc_common)

Error in `count()`:
! Must group by variables found in `.data`.
✖ Column `spc_common` is not found.

points_sf <- df %>%
  filter(spc_common %in% top9_species) %>%
  select(longitude, latitude, spc_common) %>%
  na.omit() %>%
  st_as_sf(coords = c("longitude", "latitude"), crs = 4326)

Error in `filter()`:
ℹ In argument: `spc_common %in% top9_species`.
Caused by error:
! object 'spc_common' not found

ggplot() + 
  geom_sf(data = boroughs) +
  geom_sf(data = points_sf, size = 0.1) + 
  facet_wrap(~ spc_common) +
  theme_minimal() +
  labs(title = "Top 9 Tree Species by Location")

Error:
! object 'points_sf' not found

boroughs <- read_sf("data/nyc_boroughs/nybb.shp")

top3_species <- df %>%
  count(spc_common, sort = TRUE) %>%
  slice_head(n = 3) %>%
  pull(spc_common)

Error in `count()`:
! Must group by variables found in `.data`.
✖ Column `spc_common` is not found.

points_sf <- df %>%
  filter(spc_common %in% top3_species) %>%
  select(longitude, latitude, spc_common) %>%
  na.omit() %>%
  st_as_sf(coords = c("longitude", "latitude"), crs = 4326)

Error in `filter()`:
ℹ In argument: `spc_common %in% top3_species`.
Caused by error:
! object 'spc_common' not found

ggplot() + 
  geom_sf(data = boroughs) +
  geom_sf(data = points_sf, aes(color = spc_common),
          size = 0.1) + 
  theme_minimal() +
  labs(title = "Top 3 Tree Species by Location")

Error:
! object 'points_sf' not found

points_sf <- df %>%
  filter(spc_common == "red maple") %>%
  select(longitude, latitude) %>%
  drop_na() %>%
  st_as_sf(coords = c("longitude", "latitude"), crs = 4326)

Error in `filter()`:
ℹ In argument: `spc_common == "red maple"`.
Caused by error:
! object 'spc_common' not found

ggplot() + 
  geom_sf(data = boroughs) +
  geom_sf(data = points_sf, size = 0.1) + 
  theme_minimal() +
  labs(title = "Red Maple Trees in NYC")

Error:
! object 'points_sf' not found

top15_species <- df %>%
  group_by(spc_common) %>%
  summarise(avg_dbh = mean(tree_dbh, na.rm = TRUE),
            n = n()) %>%
  filter(n >= 50) %>%
  slice_head(n = 15)

Error in `group_by()`:
! Must group by variables found in `.data`.
✖ Column `spc_common` is not found.

ggplot(top15_species, aes(x = fct_reorder(spc_common, avg_dbh),
                        y = avg_dbh)) +
  geom_col(fill = "brown") +
  coord_flip() +
  theme_minimal() +
  labs(title = "Top 15 Tree Species by Average Diameter",
       x = "Species",
       y = "Average Diameter (DBH)")

Error:
! object 'top15_species' not found

7.3.1 Question 1

7.3.2 Question 2

7.3.3 Question 3

7.4 Conclusion