HW 17 Solution.               3/28/08
==============

        libname home ".";
        options nocenter linesize=80;

       data home.PBC (drop=labels1-labels10);
         infile "ASCdata/pbcdata.asc";
         if _N_=1 then input labels1-labels10 $ ;
         else input obs idnum dth evttime treatgp logbili
            agevar cirrh cchol albumin;
         if obs ne . ;
       run;

.. "Invalid data" errors for the fields in the blank line!!
NOTE: The data set HOME.PBC has 216 observations and 10 variables.

     proc print;
        where obs < 6;
     run;

 Obs  obs  idnum  dth evttime treatgp logbili  agevar cirrh cchol albumin

  1    1    180    0    0       1     1.00000  36.598   0    0      37
  2    2    188    0    0       0     1.36173  29.964   0    0      35
  3    3     56    0    0       1     0.77815  81.451   0    0      36
  4    4     19    0    0       0     1.92428 121.510   1    0      41
  5    5    190    0    0       1     1.00000  60.340   0    0      32

(ii)  proc means data=home.pbc mean N ;
      class treatgp;
       var agevar;   run;

             Analysis Variable : agevar

            N
treatgp    Obs            Mean      N
------------------------------------------
      0    112      55.1976134    112
      1    104      51.0668269    104
------------------------------------------

/* OR */
     proc means data=home.pbc NOPRINT ;
       class treatgp;
       var agevar;
         output out = outpbc mean = AvAge N = NumAge;
     data outpbc (keep = treatgp AvAge NumAge);
        set outpbc;
        if treatgp ne .; 
     proc print; run;

                             Num
Obs    treatgp     AvAge     Age

 1        0       55.1976    112
 2        1       51.0668    104


(iii)  proc means data=home.pbc min max Q1 Q3 mean median std;
          var logbili albumin;
                                                   Lower         Upper
Variable         Minimum         Maximum        Quartile      Quartile    
          Mean          Median         Std Dev
-------------------------------------------------------------------------
logbili        0.6989700       2.7226300       1.1760900     1.8692300
       1.5404650       1.4982550       0.4472689
albumin       20.0000000      56.5000000      30.2500000    38.0000000      
      34.4643519      34.6000000       5.8433486
-------------------------------------------------------------------------

     proc means data=home.pbc;   
        /* could have omitted std dev by declaring only min max */
       class dth treatgp cirrh cchol;
        var logbili ;    run;
                                              Analysis Variable : logbili
                              N
 dth  treatgp cirrh   cchol  Obs    N          Mean       Std Dev       Minimum       Maximum
---------------------------------------------------------------------------------------------
   0        0     0       0   42   42     1.2552036     0.3042317     0.8451000     2.0718800
                          1    6    6     1.5893783     0.5487445     0.8451000     2.1731900
                  1       0   11   11     1.5182145     0.3039885     1.1139400     1.9242800
            1     0       0   40   40     1.1803825     0.2824237     0.6989700     1.9637900
                          1    4    4     1.9262925     0.2349963     1.7403600     2.2695100
                  1       0   10   10     1.5392970     0.2478913     1.2041200     1.9867700
  1         0     0       0   22   22     1.7462450     0.3479799     1.0000000     2.4653800
                          1   11   11     2.2100409     0.3302073     1.4771200     2.7226300
                  1       0   16   16     1.8077156     0.4069173     1.2041200     2.5078600
                          1    4    4     2.0339575     0.4386926     1.4471600     2.4683500
            1     0       0   23   23     1.4886604     0.4015117     0.7781500     2.3463500
  1         1     0       1    6    6     1.7670083     0.4753476     1.2552700     2.5611000
                  1       0   15   15     1.7215173     0.2145854     1.3222200     2.0334200
                          1    6    6     2.1701167     0.3167224     1.7160000     2.6263400
---------------------------------------------------------------------------------------------

/* NOTE that not all cases occur !!! */

(v) In the mean unix directory in WAM,after executing "tap SAS" and
"tap R" and starting R session:

> library(foreign)
> tmpPBC = read.ssd(".","pbc")
> dim(tmpPBC)
[1] 216  10
> names(tmpPBC)
 [1] "OBS"     "IDNUM"   "DTH"     "EVTTIME" "TREATGP" "LOGBILI" "AGEVAR"
 [8] "CIRRH"   "CCHOL"   "ALBUMIN"

> tmpPBC[1:6,]
  OBS IDNUM DTH EVTTIME TREATGP LOGBILI  AGEVAR CIRRH CCHOL ALBUMIN
1   1   180   0       0       1 1.00000  36.598     0     0      37
2   2   188   0       0       0 1.36173  29.964     0     0      35
3   3    56   0       0       1 0.77815  81.451     0     0      36
4   4    19   0       0       0 1.92428 121.510     1     0      41
5   5   190   0       0       1 1.00000  60.340     0     0      32
6   6   243   0       0       1 1.98677  29.964     1     0      34