inst/doc/snotelr-vignette.R

In snotelr: Calculate and Visualize 'SNOTEL' Snow Data and Seasonality

## ----setup, include = FALSE---------------------------------------------------
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

# load the library
library(snotelr)

# check cran, same routine as skip_on_cran()
# but not dependent on testthat which might
# not be available on user systems (not required
# only suggested)
check_cran <- function() {
  if (identical(tolower(Sys.getenv("NOT_CRAN")), "true")) {
    return(TRUE)
  } else {
    return(FALSE)
  }
}

# do cran check
cran <- check_cran()

# for local render set to true
# mainly important for rendering
# a website using pkgdown
#cran <- TRUE

## ----eval = cran--------------------------------------------------------------
#  # download and list site information
#  site_meta_data <- snotel_info()
#  head(site_meta_data)

## ----eval = cran--------------------------------------------------------------
#  # downloading data for a random site
#  snow_data <- snotel_download(
#    site_id = 670,
#    internal = TRUE
#    )
#  
#  # show the data
#  head(snow_data)

## ----fig.width = 7, fig.height=3, eval = cran---------------------------------
#  # A plot of snow accummulation through the years
#  plot(as.Date(snow_data$date),
#       snow_data$snow_water_equivalent,
#       type = "l",
#       xlab = "Date",
#       ylab = "SWE (mm)"
#      )

## ----eval = cran--------------------------------------------------------------
#  # calculate snow phenology
#  phenology <- snotel_phenology(snow_data)

## ----fig.width = 7, fig.height=3, eval = cran---------------------------------
#  # subset data to the first decade of the century
#  snow_data_subset <- subset(snow_data, as.Date(date) > as.Date("2000-01-01") &
#                               as.Date(date) < as.Date("2010-01-01"))
#  
#  # plot the snow water equivalent time series
#  plot(as.Date(snow_data_subset$date),
#       snow_data_subset$snow_water_equivalent,
#       type = "l",
#       xlab = "Date",
#       ylab = "SWE (mm)"
#    )
#  
#  # plot the dates of first snow accumulation as a red dot
#  points(phenology$first_snow_acc,
#         rep(1,nrow(phenology)),
#         col = "red",
#         pch = 19,
#         cex = 0.5
#        )