Compute annual summaries of water quality observations.
summarise_for_trends(
data,
breaks = NULL,
FUN = "median",
messages = getOption("wqbc.messages", default = TRUE)
)Arguments
- data
The data.frame to analyse.
- breaks
A numeric vector used to create groups of consecutive months, if NULL the full year is used.
- FUN
The function to use for yearly summaries, e.g. median, mean, or max.
- messages
A flag indicating whether to print messages.
Value
A tibble data.frame with rows for each Station, Variable, Year and month grouping.
Details
The data must contain the columns Station, Date, Variable, Value, and Units.
Examples
# select one station
data(yuepilon)
data <- yuepilon[yuepilon$Station == "02EA005", ]
# estimate trend (using simple sen slope)
trend <- test_trends(data, messages = TRUE)
# get the data used in the test
datasum <- summarise_for_trends(data)
plot(datasum$Year, datasum$Value,
main = paste("p-value =", round(trend$significance, 3)),
ylab = "Value", xlab = "Year", las = 1
)
