vignettes/myvignette.R

In sonam-sharma/addrepo: Geographical Map for Fatal injuries in motor vehicle traffic crashes

## ------------------------------------------------------------------------
library(dplyr)
list.files()
file.exists("accident_2013.csv")

## ----reading the file, include = TRUE------------------------------------
fars_read <- function(filename) {
 
   tryCatch({
  data1 <- suppressMessages({
 lapply(system.file('extdata', filename, package = 'mynewpackage'), read.csv)
  })
  },
  error = function(e) {
      stop("file '", filename, "' does not exist")
  })
  

 data2<-as.data.frame(data1) 
  dplyr::tbl_df(data2)
}

#head(data1)
fars_read("accident_2013.csv")


## ----generating file name,include=TRUE-----------------------------------
make_filename <- function(year) {
  year <- as.integer(year)
  sprintf("accident_%d.csv", year)

}
make_filename(2013)


## ----return year and month,include=TRUE----------------------------------
fars_read_years <- function(years) {
  file<-dat<-MONTH<-NULL
  lapply(years, function(year) {
    file <- make_filename(year)
    
    tryCatch({
     dat <- fars_read(file)
    dat%>%dplyr::mutate_( year = ~year) %>%
        dplyr::select_(~MONTH, ~year)
     
    }, 
    error = function(e) {
      warning("invalid year: ", year)
      return(NULL)
    })
  })
}
fars_read_years(2013)

## ----summarize years,include=TRUE----------------------------------------
fars_summarize_years <- function(years) {
  dat_list <- fars_read_years(years)
  dplyr::bind_rows(dat_list) %>%
    dplyr::group_by_(~year, ~MONTH) %>%
    dplyr::summarize_(n = ~n()) %>%
    tidyr::spread_(key_col='year',value_col='n')
}
fars_summarize_years(2013)

## ----map state,include=TRUE----------------------------------------------
fars_map_state <- function(state.num, year) {
  filename <- make_filename(year)
  data <- fars_read(filename)
  state.num <- as.integer(state.num)

 # if(!(state.num %in% unique(data["STATE"])))
  #  stop("invalid STATE number: ", state.num)
  data.sub <- dplyr::filter_(data, ~STATE == state.num)
  if(nrow(data.sub) == 0L) {
    message("no accidents to plot")
    return(invisible(NULL))
  }
  is.na(data.sub$LONGITUD) <- data.sub$LONGITUD > 900
  is.na(data.sub$LATITUDE) <- data.sub$LATITUDE > 90
  with(data.sub, {
    maps::map("state", ylim = range(LATITUDE, na.rm = TRUE),
              xlim = range(LONGITUD, na.rm = TRUE))
    graphics::points(LONGITUD, LATITUDE, pch = 46)
  })
}


fars_map_state(1,2013)