Checking points and filtering incorrect or unneeded data.

geofilter.R

library(tidyverse)
library(maps)
library(mapdata)

data <- read_csv("~/Desktop/nplsuperfund.csv")
names(data) <- c("lat","lon","date")

# Filter down to USA extent to remove extraneous points
tidy <- data %>% 
  filter(lat < -67, lat > -125) %>% 
  filter(lon > 25, lon < 50)
 
# Basemap
usa <- map_data("usa")

# Check data with a plot
ggplot() + 
  geom_polygon(data = usa, aes(x=long, y = lat, group = group)) + 
  geom_point(data = tidy, aes(x = lat, y =  lon), color = "red") +
  coord_fixed(1.3)

write_csv(tidy, "tidy.csv")