Spending_Function_Overview
                        4.0: Spending function overview
checkLengths            Utility functions to verify variable properties
ciBinomial              Testing, Confidence Intervals, Sample Size and
                        Power for Comparing Two Binomial Rates
condPower               Sample size re-estimation based on conditional
                        power
eEvents                 Expected number of events for a time-to-event
                        study
gsBinomialExact         One-Sample Binomial Routines
gsBound                 Boundary derivation - low level
gsBoundCP               Conditional Power at Interim Boundaries
gsCP                    Conditional and Predictive Power, Overall and
                        Conditional Probability of Success
gsDensity               Group sequential design interim density
                        function
gsDesign                Design Derivation
gsDesign package overview
                        1.0 Group Sequential Design
gsProbability           Boundary Crossing Probabilities
hGraph                  Create multiplicity graphs using ggplot2
nNormal                 Normal distribution sample size (2-sample)
normalGrid              Normal Density Grid
plot.gsDesign           Plots for group sequential designs
print.nSurv             Advanced time-to-event sample size calculation
print.nSurvival         Time-to-event sample size calculation
                        (Lachin-Foulkes)
sequentialPValue        Sequential p-value computation
sfExponential           Exponential Spending Function
sfHSD                   Hwang-Shih-DeCani Spending Function
sfLDOF                  Lan-DeMets Spending function overview
sfLinear                Piecewise Linear and Step Function Spending
                        Functions
sfLogistic              Two-parameter Spending Function Families
sfPoints                Pointwise Spending Function
sfPower                 Kim-DeMets (power) Spending Function
sfTDist                 t-distribution Spending Function
sfTruncated             Truncated, trimmed and gapped spending
                        functions
summary.gsDesign        Bound Summary and Z-transformations
xtable                  xtable
