options ls=85 nodate;

Data Weather;
 Title 'Lows and Highs from N&O Jan 28,29,30 1992';
 Title2 'using actual numbers (yesterday values)';
 input city $ hi2 lo2 yhi ylo thi tlo;

*             Mon        Tues       Wed  ;
cards;
seattle      51 44      52 44      59 47
boston       29 12      32 29      44 28
richmond     47 23      55 40      51 28
louisville   53 30      37 29      46 24
lubbock      46 40      48 42      54 42
omaha        31 26      36 22      47 31
sanfran      56 47      65 49      65 47
philly       36 18      46 27      46 26
cincinnati   50 25      36 29      41 30
phoenix      74 49      75 48      75 48
miami        72 68      77 71      79 72
milwauke     31 23      33 26      35 26
dallas       50 47      53 47      56 44
burlingvt    20 -2      28 03      39 24
buffalo      34 18      34 28      32 26
charlotte    49 38      60 41      59 41
bismark      27 -5      43 15      47 17
elpaso       61 34      64 33      64 32
rapidcity    46 20      62 25      57 41
 ;
proc reg; model thi = yhi hi2 tlo ylo lo2/ss1 ss2;
   test tlo=0, ylo=0, lo2=0;

 /*-----------------------------------------------
 |  Showing sequential and partial sums of squares|
 | Note t**2 = F relationship for partial F.  By  |
 | hand, construct F to leave out lows.  Compare  |
 | to test statement.                             |
  -----------------------------------------------*/

proc reg; model thi = yhi hi2;

 /*--------------------------------------------------
 |  Use this to construct full vs. reduced model F   |
 | Compare to previous results.                      |
 | Note decrease in model SS = increase in error SS. |
  --------------------------------------------------*/

proc reg; model thi = hi2 tlo ylo lo2 yhi/ss1 ss2;

 /*---------------------------------------------------
 |  How do sequential and partial for yhi here compare |
 | to first regression?  Note that partial SS for any  |
 | variable is sequential SS I WOULD have gotten if    |
 | that variable were fitted last.                     |
  ----------------------------------------------------*/

run;