# v0.1.1 Dec 17, 2020
#  (1) fixed a bug in function 'ssizeEpiCont': sigma2 <- var(X1) should be sigma2 <- var(X1, na.rm=TRUE)
#      Thank Prof. Annabelle Rodriguez-Oquendo <rodriguezoquendo@uchc.edu> for reporting this bug
#  (2) simplify R code
#  (3) change maintainer's email to weiliang.qiu@gmail.com
#
# v0.1.0 Feb 7, 2018
#  (1) Thank Aurélien Latouche <aurelien.latouche@lecnam.net> for pointing out a typo in the Notes of several Rd files. The correct one is:
#      "In Latouche et al. (2004), the hazard ratio θ measures the difference of effect of a covariate  on  the subdistribution hazard ratio
#       , while in Schoenfeld (1983),  on the cause specific hazard ratio."
#
# v0.0.9 July 23, 2015
#   (1) explicitly import 'optim' function in 'NAMESPACE'
#   
# v0.0.8 July 22, 2015
#  (1) rename 'log.txt' as 'NEWS'
#  (2) fixed a warning: 
#  The Title field should be in title case, current version then in title case:
#  'Power and sample size calculation for survival analysis of epidemiological studies'
#  'Power and Sample Size Calculation for Survival Analysis of Epidemiological Studies'
#
# v0.0.7 April 1, 2012
#  (1) change 'GPL version 2 or newer' to 'GPL (>=2)
#       in the file 'DESCRIPTION'
#
# v0.0.6 March 28, 2012
#   (1) added functions 'power.stratify' and 'ssize.stratify'
#       to calculate power/sample size for stratified survival analysis
#
 
