UKFE (version 1.0.2)

EVPool: Extreme value plot for pooling groups

Description

Plots the extreme value frequency curve or growth curve for gauged or ungauged pooled groups

Usage

EVPool(
  x,
  AMAX = NULL,
  gauged = FALSE,
  dist = "GenLog",
  QMED = NULL,
  Title = "Pooled growth curve",
  UrbAdj = FALSE,
  CDs
)

Value

An extreme value plot for gauged or ungauged pooling groups

Arguments

x

pooling group derived from the Pool() function

AMAX

the AMAX sample to be plotted in the case of gauged. If NULL, & gauged equals TRUE, the AMAX from the first site in the pooling group is used

gauged

logical argument with a default of FALSE. If FALSE, the plot is the ungauged pooled curve accompanied by the single site curves of the group members. If TRUE, the plot is the gauged curve and single site curve with the observed points added

dist

a choice of distribution. Choices are "GEV", "GenLog", "Kappa3", or "Gumbel". The default is "GenLog"

QMED

a chosen QMED to convert the curve from a growth curve to the frequency curve

Title

a character string. The user chosen plot title. The default is "Pooled growth curve"

UrbAdj

a logical argument with a default of FALSE. If TRUE an urban adjustment is applied to the pooled growth curve

CDs

catchment descriptors derived from either GetCDs or CDsXML. Only necessary if UrbAdj is TRUE

Author

Anthony Hammond

Examples

# Get some CDs, form an ungauged pooling group and apply EVPool
cds_28015 <- GetCDs(28015)
pool_28015 <- Pool(cds_28015, exclude = 28015)
EVPool(pool_28015)

# Do the same for the gauged case, change the title, and convert with a QMED of 9.8
pool_g_28015 <- Pool(cds_28015)
EVPool(pool_g_28015, gauged = TRUE, Title = "Gauged frequency curve - Site 28015", QMED = 9.8)

# Pretend we have an extra AMAX for the gauge. Amend the pooling group Lcv and LSkew
# for the site accordingly, then apply EVPool with the updated AMAX
# Firstly, get the AMAX sample
am_28015 <- GetAM(28015)

# Add an extra AMAX flow of 15 m^3/s
append_28015 <- append(am_28015$Flow, 15)

# Amend the Lcv and Lskew in the pooling group
pool_g_28015[1, c(16, 17)] <- c(Lcv(append_28015), LSkew(append_28015))

# Now plot gauged with the updated AMAX
EVPool(pool_g_28015, AMAX = append_28015, gauged = TRUE)