R/helpers_plot.R

In Centre-for-Marine-Applied-Research/strings: Compile, Format, and Visualize Sensor String Data

#'@title Returns nice major and minor breaks and label format based on timespan
#'  of the data
#'@details If the timespan in the \code{TIMESTAMP} column of \code{dat.tidy} is
#'  less than or equal to 60 days, the major and minor breaks will be every 2
#'  weeks; if time span is greater than 60 days and less than or equal to 120
#'  days, the major and minor breaks will be every month; if time span is
#'  greater than 120 days and less than or equal to 240 days, the major breaks
#'  will be 2 months and the minor breaks will be 1 month; if the time span is
#'  greater than 240 days, the major breaks will be 4 months and the minor
#'  breaks will be 1 month.
#'@param dat.tidy Data to be plotted, in tidy format, as returned by the
#'  function \code{convert_to_tidydata()}. Must include the column
#'  \code{TIMESTAMP} (POSIXct).
#'@return Returns a dataframe with 1 observation of 3 variables
#'  \code{date.breaks.major}, \code{date.breaks.minor},
#'  \code{date.labels.format}.

#'@family plot
#'@author Danielle Dempsey
#'@export


get_xaxis_breaks <- function(dat.tidy){

  # timespan of the data
  timespan <- difftime(max(dat.tidy$TIMESTAMP), min(dat.tidy$TIMESTAMP), units = "days")
  timespan <- unclass(timespan)[1]

  if(timespan <= 60){
    date.breaks.major = "2 week"
    date.breaks.minor = "2 week"
    date.labels.format = "%y-%b-%d"
  }

  if(60 < timespan & timespan <= 120){
    date.breaks.major = "1 month"
    date.breaks.minor = "1 month"
    date.labels.format = "%y-%b"
  }

  if(timespan > 120 & timespan <= 240){
    date.breaks.major = "2 month"
    date.breaks.minor = "1 month"
    date.labels.format = "%y-%b"
  }

  if(timespan > 240 & timespan <= 1095){
    date.breaks.major = "4 month"
    date.breaks.minor = "1 month"
    date.labels.format = "%y-%b"
  }

  if(timespan > 1095 & timespan <= 2555){
    date.breaks.major = "6 month"
    date.breaks.minor = "1 month"
    date.labels.format = "%y-%b"
  }

  if(timespan > 2555){
    date.breaks.major = "1 year"
    date.breaks.minor = "2 month"
    date.labels.format = "%Y-%b"
  }


  data.frame(date.breaks.major = date.breaks.major,
             date.breaks.minor = date.breaks.minor,
             date.labels.format = date.labels.format)

}



#'@title Returns nice colour palette based on the number of unique DEPTH values
#'@details If there are 6 or less unique values of \code{DEPTH}, returns a
#'  discrete viridis colour palette with 6 colours (Option D). If there are more
#'  than 6 unique values of \code{DEPTH}, returns a discrete colour palette with
#'  the number of colours equal to the number of unique values of \code{DEPTH}.
#'@param dat.tidy Data to be plotted, in tidy format, as returned by the
#'  function \code{convert_to_tidydata()}. Must include the column
#'  \code{DEPTH}.
#'@return Returns a vector of hex colours from the viridis palette

#'@family plot
#'@author Danielle Dempsey
#'@export
#'

get_colour_palette <- function(dat.tidy){

  n.depth <- length(unique(dat.tidy$DEPTH))

  if(n.depth > 6){
    color.palette <- viridis(n.depth, option = "D", direction = -1)
  } else{
    color.palette <- viridis(6, option = "D", direction = -1)
  }

  color.palette

}