Function gLRT4
conducts a k(=2)sample test for intervalcensored survival data. The test is based on Zhao, Duan, Zhao, and Sun (2013). The null hypothesis is that the two survival functions of the failure time are the same, and the alternative hypothesis is that the two functions are not the same.
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A 
an n by 3 data matrix with the censoring interval of the format (L, R] in columns 1 & 2 and treatmentment indicator ranging from 0 to k1 in column 3. No exact observations (i.e., L = R) are allowed. 
k 
number of treatments. Only k = 2 is allowed. 
rho 
nonnegative parameter in [0, 1] of the link function used for calculating the test statistics. It is the same as b in Zhao, Duan, Zhao, and Sun (2013). The default is 0. 
gamma 
nonnegative parameter in [0, 1] of the link function used for calculating the test statistics. It is the same as c in Zhao, Duan, Zhao, and Sun (2013). The default is 0. 
EMstep 
a boolean variable indicating whether to take an EM step in the iteration when estimating the common distribution function. The default is TRUE. 
ICMstep 
a boolean variable indicating whether to take an ICM step in the iteration when estimating the common distribution function. The default is TRUE. 
tol 
the maximal L_1 distance between successive estimates before stopping iteration when estimating the common distribution function. The default is 1.0e6. 
maxiter 
the maximal number of iterations to perform before stopping when estimating the common distribution function. The default is 1000. 
inf 
value used in data for infinity. The default is Inf. 
The NPMLE of the distribution function for each treatment group is computed by function ModifiedEMICM
.
The ftest in gLRT4
is based on an F distribution with degrees of freedom 1 and 1.
The link function used in gLRT4
is ξ(x) = x log(x) x^ρ (1  x)^γ = x log(x) x^b (1  x)^c.
The function returns an object containing the following components:
method 
test procedure used 
u 
the test statistic 
v 

fstat 
the ftest statistic 
df 
the numerator and denominator degrees of freedom of the ftest, i.e., (1, 1) 
p 
pvalue of the ftest 
Qiang Zhao and Jianguo Sun
X. Zhao, R. Duan, Q. Zhao, and J. Sun (2013), "A New Class of Generalized Log Rank Tests for Intervalcensored Failure Time Data", Computational Statistics and Data Analysis. 60: 123131.
gLRT
, gLRT1
, gLRT2
, gLRT3
, ScoreTest
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