s-news
[Top] [All Lists]

[no subject]

To: <s-news@wubios.wustl.edu>
From: "Niels Waller" <ngwaller@ucdavis.edu>
Date: Tue, 25 Aug 1998 18:13:35 -0700
Sender: owner-s-news@wubios.wustl.edu
I would greatly appreciate any help with the following problem.

I want to generate a pair of vectors with the following properties.  Each
vector has N elements.


(1) the vector entries equal 0 or 1
(2) BR percent of each vector contains 1's - the remaining elements equal 0
(BR = base rate of disease in population)
(3) the vectors satisfy the following criteria

[pseudo code]
for (i in 1:N){
if(VecA[i]==1 & VecB[i]==1)  we have a match
}

Def:
concordance = (2 x # matches)/(N+ # matches)

I want to generate data that simultaneously satisfies a given Base rate (BR)
_AND_ a given concordance rate.


In genetics, the above concordance rate is called a probandwise concordance
rate among twins.


Many thanks for any suggestions.  I am pulling my hair out over this one!


********************************************************************
Niels Waller, Ph.D.
Associate Professor

Address: One Shields Avenue      Phone: (530) 752-4459
Department of Psychology
University of California
Davis, CA 95616

Internet: http://psychology.ucdavis.edu/waller
********************************************************************

-----------------------------------------------------------------------
This message was distributed by s-news@wubios.wustl.edu.  To unsubscribe
send e-mail to s-news-request@wubios.wustl.edu with the BODY of the
message:  unsubscribe s-news

<Prev in Thread] Current Thread [Next in Thread>
  • [no subject], Niels Waller <=