wilcoxon.sas, * example from SAS documentation;
options ls=76 nodate;
;
data React;
input Stim Time @@;
datalines;
1 1.94 1 1.94 1 2.92 1 2.92 1 2.92 1 2.92 1 3.27
1 3.27 1 3.27 1 3.27 1 3.70 1 3.70 1 3.74
2 3.27 2 3.27 2 3.27 2 3.70 2 3.70 2 3.74
;
proc npar1way wilcoxon correct=no data=React;
class Stim;
var Time;
exact wilcoxon;
title 'Illustration of Wilcoxon Rank Sum Test';
;
proc rank ties=mean out=rrank;
var Time;
ranks rank;
title2 'Compute rank sum for stim=2';
data rrank; set rrank;
rank = (rank)*(stim-1); * gives rank if stim=2, else zero;
proc sort; by Time;
proc print;
proc means sum;
var rank;
Illustration of Wilcoxon Rank Sum Test 1
The NPAR1WAY Procedure
Wilcoxon Scores (Rank Sums) for Variable Time
Classified by Variable Stim
Sum of Expected Std Dev Mean
Stim N Scores Under H0 Under H0 Score
--------------------------------------------------------------------
1 13 110.50 130.0 11.004784 8.500
2 6 79.50 60.0 11.004784 13.250
Average scores were used for ties.
Wilcoxon Two-Sample Test
Statistic (S) 79.5000
Normal Approximation
Z 1.7720
One-Sided Pr > Z 0.0382
Two-Sided Pr > |Z| 0.0764
t Approximation
One-Sided Pr > Z 0.0467
Two-Sided Pr > |Z| 0.0933
Exact
Test
One-Sided Pr >= S 0.0527
Two-Sided Pr >= |S - Mean| 0.1054
Kruskal-Wallis Test
Chi-Square 3.1398
DF 1
Pr > Chi-Square 0.0764
Illustration of Wilcoxon Rank Sum Test 2
Compute rank sum for stim=2
Obs Stim Time rank
1 1 1.94 0.0
2 1 1.94 0.0
3 1 2.92 0.0
4 1 2.92 0.0
5 1 2.92 0.0
6 1 2.92 0.0
7 1 3.27 0.0
8 1 3.27 0.0
9 1 3.27 0.0
10 1 3.27 0.0
11 2 3.27 10.0
12 2 3.27 ...