Delta values from Table 9-3 of Kite (2004) see https://tonyladson.wordpress.com/2015/03/31/delta-values-for-flood-frequency-confidence-limits/

DeltaTable_Kite.R

# Usage
#
# source_gist('https://gist.github.com/TonyLadson/280fd3ae3e730b3bb370')
# DeltaTable_Kite(g = 0.1, aep = 0.02)
# [1] 2.3425

DeltaTable_Kite <- function(g, aep){
  
  # g = skew
  # aep = annual exceedance probability
  # Table 9-3
  # Kite, G. W. (2004) Frequency and risk analysis in hydrology.
  # Water Resources Publications, Littleton Co
  
  
  require(e1071)
  
  if(g > 2 | g < 0) stop('To use delta values from Kite, g must be in the range 0 to 2')
  if(aep < 0.01 | aep > 0.5) stop('To use delta values from Kite, AEP must be in the range 0.01 to 0.5')
  if(length(aep) > 1 | length(g) >1) stop('g and AEP cannot have length greater than 1')
  
  # load in delta values from Table 9-3 of Kite (2004)
  
delta.table <-
    structure(c(1.0801, 1.0808, 1.083, 1.0866, 1.0918, 1.0987, 1.1073, 
                1.1179, 1.1304, 1.1449, 1.1614, 1.1799, 1.2003, 1.2223, 1.2457, 
                1.2701, 1.2952, 1.3204, 1.3452, 1.369, 1.3913, 1.1698, 1.2006, 
                1.2309, 1.2609, 1.2905, 1.3199, 1.3492, 1.3785, 1.4082, 1.4385, 
                1.4699, 1.503, 1.5382, 1.5764, 1.6181, 1.6643, 1.7157, 1.7732, 
                1.8374, 1.9091, 1.9888, 1.3748, 1.4367, 1.4989, 1.561, 1.6227, 
                1.6838, 1.7441, 1.8032, 1.8609, 1.917, 1.9714, 2.024, 2.0747, 
                2.1237, 2.1711, 2.2173, 2.2627, 2.3081, 2.3541, 2.4018, 2.4525, 
                1.6845, 1.781, 1.8815, 1.9852, 2.0915, 2.1998, 2.3094, 2.4198, 
                2.5303, 2.6403, 2.7492, 2.8564, 2.9613, 3.0631, 3.1615, 3.2557, 
                3.3455, 3.4303, 3.51, 3.5844, 3.6536, 2.1988, 2.3425, 2.4986, 
                2.6656, 2.8423, 3.0277, 3.2209, 3.4208, 3.6266, 3.8374, 4.0522, 
                4.2699, 4.4896, 4.71, 4.9301, 5.1486, 5.3644, 5.5761, 5.7827, 
                5.9829, 6.1755, 2.6363, 2.8168, 3.0175, 3.2365, 3.4724, 3.7238, 
                3.9895, 4.2684, 4.5595, 4.8618, 5.1741, 5.4952, 5.824, 6.1592, 
                6.4992, 6.8427, 7.1881, 7.5339, 7.8783, 8.2196, 8.5562), 
              .Dim = c(21L, 6L), 
              .Dimnames = list(seq(0,2,0.1),                                # row names
                               c("0.5", "0.2", "0.1", "0.05", "0.02", "0.01")))  # col names
  
  
  delta.table <- delta.table[ ,6:1] # we need to re-order the data so its from lowest to highest value in each dimension
  
  interpolate(c(g, aep), delta.table)

}