Appendix B: Sashelp Data Sets

Tropical Rain Forest Tree Data

The Sashelp.BEI data set contains the locations of 3,604 trees in a number of tropical rain forests (Condit 1998; Hubbell and Foster 1983; Condit, Hubbell, and Foster 1996). A study window of 1,000 times 500 square kilometers is used. The data set also contains covariates, represented by the variables Gradient and Elevation, which were collected at over 20,301 locations on a regular grid across the study region. The variable Trees distinguishes the event observations in the data set. The following steps display information about the data set Sashelp.BEI and create Figure 44: 

title 'BEI Data';
proc contents data=sashelp.bei varnum;
   ods select position;
run;

title 'The First Five Observations Out of 23,905';
proc print data=sashelp.bei(obs=5);
run;

title 'The Trees Variable';
proc freq data=sashelp.bei;
   tables Trees;
run;

Figure 44: Tropical Rain Forest Tree Data

BEI Data

Variables in Creation Order
# Variable Type Len
1 X Num 8
2 Y Num 8
3 Elevation Num 8
4 Gradient Num 8
5 Aluminum Num 8
6 Boron Num 8
7 Calcium Num 8
8 Copper Num 8
9 Iron Num 8
10 Potassium Num 8
11 Magnesium Num 8
12 Manganese Num 8
13 Sodium Num 8
14 Phosphorus Num 8
15 Sulphur Num 8
16 Zinc Num 8
17 Ammonia Num 8
18 Nitrate Num 8
19 TotalNitro Num 8
20 MinAmmonia Num 8
21 MinNitrate Num 8
22 MinNitrogen Num 8
23 pH Num 8
24 Trees Num 8

The First Five Observations Out of 23,905

Obs X Y Elevation Gradient Aluminum Boron Calcium Copper Iron Potassium Magnesium Manganese Sodium Phosphorus Sulphur Zinc Ammonia Nitrate TotalNitro MinAmmonia MinNitrate MinNitrogen pH Trees
1 11.7 151.1 . . . . . . . . . . . . . . . . . . . . . 1
2 998.9 430.5 . . . . . . . . . . . . . . . . . . . . . 1
3 980.1 433.5 . . . . . . . . . . . . . . . . . . . . . 1
4 986.5 425.8 . . . . . . . . . . . . . . . . . . . . . 1
5 944.1 415.1 . . . . . . . . . . . . . . . . . . . . . 1

The Trees Variable

Trees Frequency Percent Cumulative
Frequency		 Cumulative
Percent
0 20601 85.11 20601 85.11
1 3604 14.89 24205 100.00


Last updated: December 09, 2022