ch_polar_plot_prep: Creates a data structure to be passed to `ch_polar_plot`

Description

Could be used to move data from a different type of analysis different to the ch_binned_MannWhitney function which uses flows. The two series need to be of the same length and their length is related to the step size. For examples, for five day periods there will be 73 periods.

Usage

ch_polar_plot_prep(
  station,
  plot_title,
  step,
  x0,
  x1,
  stat,
  prob,
  test_s,
  variable = "discharge",
  bin_method = "unstated",
  test_method = "unstated",
  lline1 = "Period 1",
  lline2 = "Period 2",
  pvalue = 0.05
)

Value

Returns a list containing:

StationID: ID of station
Station_lname: Name of station
variable: Name of variable
bin_width: Smoothing time step in days
range1: First range of years
range2: Second range of years
p_used: p_value
fail: TRUE if test failed due to missing values
bin_method: Method used for binning
test_method: Mann-Whitney U
series: A data frame containing six columns

The series data frame contains

period: period numbers i.e. 1:365/step
period1: median values for each bin in period 1
period2: median values for each bin in period 2
mwu: Mann Whitney U-statistic for each bin between the two periods
prob: probability of U for each period
code: significance codes for each bin

Arguments

station: Typically a station number
plot_title: Polar plot title - usually a station name
step: The number of days binned
x0: Time series of length n for a single seasonal cycle
x1: Time series of length n for a single seasonal cycle
stat: Time series of length n for statistical test value for each bin
prob: Time series of length n of probability of test value
test_s: Vector with values of -1, 0, 1 for significance, -1 negative, 1 positive, 0 not significant
variable: Name of variable plotted. Default is discharge
bin_method: Default is unstated
test_method: Default is unstated
lline1: Names of first period, default is Period 1
lline2: Names of second period, default is Period 2
pvalue: Value of p used. Default is 0.05

Author

Paul Whitfield

References

Whitfield, P.H. and A.J. Cannon. 2000. Polar plotting of seasonal hydrologic and climatic data. Northwest Science 74: 76-80.