st: Binomial Sign Test for Two Dependent Samples

[Thomas Speidel <thomassp@cancerboard.ab.ca>]

I am trying to create little program for a "Binomial Sign Test for Two 
Dependant Samples".
This test is somewhere between a signrank test and a binomial.  The 
computations are fairly simple:

1. Find the differences among the pairs
2. Ignore all null differences
3. Count the number of non-zero, non-missing differences (i.e. n)
4. Count the number of positive differences (call it x)
5. Compute: Binomial(n, k, 0.5)

I am trying to implement this into a little program so that I can loop 
it through a number of variables/groups.  However, because I am not an 
expert programmer, I came to a roadblock...  Following is a sample of my 
data:

NOTE:  *posneg: is the sign of the difference (i.e. 0=no difference; 
1=Positive; -1=Negative)
 +--------------------------------------------------+
 |liverid   group   mp1posneg  mp2posneg   mp3posneg|
 |--------------------------------------------------|
 |  929444       1          0         -1         -1 |
 |  948579       1         -1          0         -1 |
 |  953012       1         -1          0         -1 |
 |  956482       1         -1          0         -1 |
 |  986833       1          .          .          . |
 | 9314571       1          .          .          . |
 | 9314751       1          .         -1          . |
 | 9413243       1         -1         -1         -1 |
 | 9510420       1          .          .          . |
 | 9613027       1          .          .          . |
 | 9614920       1         -1          0         -1 |
 | 9820601       1         -1          0         -1 |
 | 9821645       1          0          0         -1 |
 | 9912795       1          0          0         -1 |
 |--------------------------------------------------|
 |   12896       2          0          0         -1 |
 |   94787       2          .         -1          0 |
 |   98613       2          .          0          . |
 |  111381       2          .          0         -1 |
 |  936134       2          0          0          0 |
 |  969968       2          .         -1          . |
 |  991853       2          .          .          . |
 | 9617199       2         -1          0         -1 |
 | 9810799       2          .          0         -1 |
 |--------------------------------------------------|
 |    9338       3          .         -1          . |
 |  953132       3         -1         -1         -1 |
 |  954005       3         -1         -1         -1 |
 +--------------------------------------------------+

I am trying to find the binomial for each variable by group
This is what I have thus far, but does not work:

foreach x of var mp1posneg mp2posneg mp3posneg {
              foreach i in 1 2 3 {
               qui count if `x'posneg==1 & group == `i'
               local pos_`i'`x' = r(N)
               qui count if `x'posneg==1 | `x'posneg==-1 & group == `i'
               local n_`i'`x'=r(N)
               display Binomial(n_`i'`x', pos_`i'`x', 0.5)
               }
       }



Thanks,
Thomas




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