DATA REACT; INPUT YIELD PH TEMP @@; PSQ=PH**2; TSQ=TEMP**2; 
PT=PH*TEMP;CARDS; 
 90 5 60 100 5 80 95 5 100 105 5.5 80 100 6 60 130 6 80 125 6 100 
140 6.5 80 135 7 60 142 7 80 126 7 100 
PROC PRINT; 
PROC REG; MODEL YIELD = PH TEMP PSQ TSQ PT/P; 
TITLE 'CHEMICAL PROCESS YIELDS'; 
PROC RSREG; MODEL YIELD = PH TEMP; 

*** Make a grid for graphics ***; 
DATA GRID; 
DO PH = 5 TO 7 BY .1; 
* DO PH = 0 TO 12 BY .2; 
DO TEMP = 60 TO 142 BY 2; ID="GRID"; OUTPUT; END; END;
DATA ALL; SET REACT GRID; 
PROC RSREG NOPRINT OUT=OUTCHEM; 
 MODEL YIELD = PH TEMP/PREDICT; 
DATA OUTCHEM; SET OUTCHEM; IF _N_>11; 
PROC G3D; PLOT PH*TEMP=YIELD; 
RUN; 
 
RUN;