/***********************************************
 *  Kleinbaum, Chapter 6, Problem #4-6, p. 105 *
 ***********************************************/

/* Create the Stata dataset */
capture clear
input person   sbp    quet   age   smk
 1   135   2.876    45     0
 2   122   3.251    41     0
 3   130   3.100    49     0
 4   148   3.768    52     0
 5   146   2.979    54     1
 6   129   2.790    47     1
 7   162   3.668    60     1
 8   160   3.612    48     1
 9   144   2.368    44     1
10   180   4.637    64     1
11   166   3.877    59     1
12   138   4.032    51     1
13   152   4.116    64     0
14   138   3.673    56     0
15   140   3.562    54     1
16   134   2.998    50     1
17   145   3.360    49     1
18   142   3.024    46     1
19   135   3.171    57     0
20   142   3.401    56     0
21   150   3.628    56     1
22   144   3.751    58     0
23   137   3.296    53     0
24   132   3.210    50     0
25   149   3.301    54     1
26   132   3.017    48     1
27   120   2.789    43     0
28   126   2.956    43     1
29   161   3.800    63     0
30   170   4.132    63     1
31   152   3.962    62     0
32   164   4.010    65     0
end

format quet %9.3f
format smk  %-9.0g

label data "Klenbaum Chapter 5, Problem #2, p. 65"
label variable person "ID"
label variable sbp    "Systolic Blood Pressure"
label variable quet   "Body Size"
label variable age    "Age"
label variable smk    "Smoker (0=no; 1=yes)"
label define yesno 0 no 1 yes
label values smk yesno

list, noobs sep(11)


quietly {
  corr quet age
  local alpha=0.01
  local z=invnormal(1-(`alpha'/2))
  local se=(r(N)-1)^.5
  local rz=.5*(ln((1+`r(rho)')/(1-`r(rho)')))
  local lb=`rz' - (`z'/`se')
  local ub=`rz' + (`z'/`se')

  local lb1 = (exp(2*`lb')-1)/(exp(2*`lb')+1)
  local ub1 = (exp(2*`ub')-1)/(exp(2*`ub')+1)
  #delimit ;
  noisily di _n "r_quet.age"
             _n _col(3) "r= "  %4.3f r(rho)   _col(12) 
                        "LB= " %4.3f `lb1'    _col(23) 
                        "UB= " %4.3f `ub1'    _col(34)
                        "r2= " %4.3f r(rho)^2 _col(46)
                        "n= "  r(N);
  #delimit cr

  corr sbp age
  local alpha=0.01
  local z=invnormal(1-(`alpha'/2))
  local se=(r(N)-1)^.5
  local rz=.5*(ln((1+`r(rho)')/(1-`r(rho)')))
  local lb=`rz' - (`z'/`se')
  local ub=`rz' + (`z'/`se')

  local lb1 = (exp(2*`lb')-1)/(exp(2*`lb')+1)
  local ub1 = (exp(2*`ub')-1)/(exp(2*`ub')+1)
  #delimit ;
  noisily di _n "r_sbp.age"
             _n _col(3) "r= "  %4.3f r(rho) _col(12) 
                        "LB= " %4.3f `lb1'  _col(23) 
                        "UB= " %4.3f `ub1'  _col(34)
                        "r2= " %4.3f r(rho)^2 _col(46)
                        "n= "  r(N);
 #delimit cr

  corr sbp smk
  local alpha=0.01
  local z=invnormal(1-(`alpha'/2))
  local se=(r(N)-1)^.5
  local rz=.5*(ln((1+`r(rho)')/(1-`r(rho)')))
  local lb=`rz' - (`z'/`se')
  local ub=`rz' + (`z'/`se')

  local lb1 = (exp(2*`lb')-1)/(exp(2*`lb')+1)
  local ub1 = (exp(2*`ub')-1)/(exp(2*`ub')+1)
  #delimit ;
  noisily di _n "r_sbp.smk"
             _n _col(3) "r= "  %4.3f r(rho) _col(12) 
                        "LB= " %4.3f `lb1'  _col(23) 
                        "UB= " %4.3f `ub1'  _col(34)
                        "r2= " %4.3f r(rho)^2 _col(46)
                        "n= "  r(N);
 #delimit cr

}