data-raw/save_weather.R

In akleinhesselink/sheepweather: USSES Soil Moisture and Weather

rm(list = ls())
library(tidyverse)
library(lubridate)
# input --------------------------------------------------- #

weather <- as.list( read_lines('data-raw/usses_weather.txt') )

# output -------------------------------------------------- #

outfile <- 'temp_data/weather.RDS'

# -------------------------------------------------- #

# each line is broken up into these sets of characters
# matrix gives start and finish character
char_mat <- matrix(
  c(sort(c(1,12,16,18, seq(22, 269, c(8)), seq(27, 269, 8), seq(28, 269, 8), seq(29, 269, 8))),
    sort(c(11,15,17,21, seq(22 + 4, 269, c(8)), seq(27, 269, 8), seq(28, 269, 8), seq(29, 269, 8)))),
  ncol = 2)

vnames <- paste(c('VALUE', 'MFLAG', 'QFLAG', 'SFLAG'), sort(rep(1:31, 4)), sep = '')
col_names <- c('ID', 'YEAR', 'MONTH', 'ELEMENT', vnames)

weather <- lapply( weather, str_sub, char_mat)

weather <- data.frame( do.call(rbind, weather) )
names(weather) <- col_names

weather <-
  weather %>%
  select( YEAR, MONTH, ELEMENT, starts_with('VALUE')) %>%
  gather(day, value, starts_with('VALUE')) %>%
  mutate( day = str_extract( day, '\\d+')) %>%
  mutate( value = as.numeric(value)) %>%
  mutate( value = ifelse( value == -9999, NA, value)) %>%
  mutate( value = ifelse(ELEMENT %in% c('TMIN', 'TMAX', 'PRCP'), value/10, value)) %>%
  mutate( YEAR = as.numeric(levels(YEAR)[YEAR]), MONTH = as.numeric(MONTH), day = as.numeric(day)) %>%
  arrange( ELEMENT, YEAR, MONTH, day)

weather <-
  weather %>%
  filter( ELEMENT %in% c('PRCP', 'TMIN', 'TMAX'))

weather <-
  weather %>%
  mutate( date = paste( YEAR, MONTH, day, sep = '-')) %>%
  mutate( date = ymd( date )) %>%
  filter( ! is.na(date)) %>%
  select( date, ELEMENT, value)

saveRDS(weather, file = outfile)