gistfile1.r

# here is the data:
# http://www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELPRDC5087258
# You'll need to remove the first two lines and save a .csv file

setwd("C:/Users/abc/Downloads")
markets <- read.csv("farmers-market.csv")
OR.markets <- markets %>%
  filter(State=="Oregon")

require(ggplot2)
require(ggmap)
lats <- OR.markets$y
lons <- OR.markets$x
library(dplyr)
Seafood <- OR.markets$Seafood
df <- as.data.frame(cbind(lons,lats))

library(maps)
Oregon.map <- map_data("state", region="Oregon")
ggplot() +
geom_polygon(data=Oregon.map, aes(x=long, y=lat, group = group),
     colour="grey", fill="white" ) +
  geom_point(data = df, aes(x = lons, y=lats, alpha = 0.2, colour=Seafood), size = 2, shape = 16) +
  guides(fill=FALSE, alpha=FALSE, size=FALSE) +
  ggtitle("Oregon Farmer's Markets")