Sashelp Data Sets


Exhaust Emissions Data

The Sashelp.Gas data set contains data from an experiment about gasoline engine exhaust emissions (Brinkman, 1981). Nitrogen oxide emissions from a single-cylinder engine are measured for various combinations of fuel, compression ratio, and equivalence ratio. This data set is used to illustrate how to fit models by using nonlinearly transformed data. The following steps display information about the Sashelp.Gas data set and create Figure B.9:

title 'Exhaust Emissions Data';
proc contents data=sashelp.Gas varnum;
   ods select position;
run;

title 'The First Five Observations Out of 171';
proc print data=sashelp.Gas(obs=5);
run;

title 'The Fuel Type Variable';
proc freq data=sashelp.Gas;
   tables fuel;
run;

Figure B.9: Exhaust Emissions Data

Exhaust Emissions Data

Variables in Creation Order
# Variable Type Len Label
1 Fuel Char 8  
2 CpRatio Num 8 Compression Ratio
3 EqRatio Num 8 Equivalence Ratio
4 NOx Num 8 Nitrogen Oxide

The First Five Observations Out of 171

Obs Fuel CpRatio EqRatio NOx
1 Ethanol 12 0.907 3.741
2 Ethanol 12 0.761 2.295
3 Ethanol 12 1.108 1.498
4 Ethanol 12 1.016 2.881
5 Ethanol 12 1.189 0.760

The Fuel Type Variable

Fuel Frequency Percent Cumulative
Frequency
Cumulative
Percent
82rongas 9 5.26 9 5.26
94%Eth 25 14.62 34 19.88
Ethanol 90 52.63 124 72.51
Gasohol 13 7.60 137 80.12
Indolene 22 12.87 159 92.98
Methanol 12 7.02 171 100.00