Plot annual maximum data from http://data.water.vic.gov.au/monitoring.htm.

PlotMax.R

# This script takes the standard download of annual max, min, mean data from
# http://data.water.vic.gov.au/monitoring.htm
# Plots a bar plot with ggplot

library(stringr)
library(dplyr)
library(lubridate)
library(ggplot2)
library(devtools)
library(scales)
library(repmis)

# Source my preferred ggplot Theme see
# see https://gist.github.com/TonyLadson/cc60bbb3cbadf0e72619
devtools::source_gist('cc60bbb3cbadf0e72619')

# Download sample data
flow <- tbl_df(source_data('https://dl.dropboxusercontent.com/u/10963448/CreswickCk%40Clunes-407214.csv', skip = 16, stringsAsFactors = FALSE))

names(flow) <- c('date.time', 'flow.mean', 'flow.mean.qc', 'flow.min', 'flow.min.qc', 'flow.max', 'flow.max.qc')

# parse dates

flow <- flow %>%
  mutate(date.time = parse_date_time(date.time, orders = 'dmy H:M:S'))

# First and last dates
flow %>%
  summarise(max(date.time), min(date.time))


# plot

flow %>%
  ggplot(aes(x = date.time, y = flow.max)) + geom_bar(stat = 'identity') + BwTheme +
  scale_x_datetime(name = 'Date', limits = c(ymd('1943-01-01'), ymd('2016-01-01')), date_breaks = '2 year', date_labels = "%Y") +
  theme(axis.text.x = element_text(angle = 90, vjust = 0.5)) +
  scale_y_continuous(name = 'Discharge (cumec)', labels = comma) +
  theme(axis.text.x = element_text(angle = 90, vjust = 0.5))