RE: Sorting of 2x2 tables (Oswego example discussion)
The problem of the /sd option in relation to tab ill cakes vanilla chocolate /oa /sd /ex versus tab ill cakes vanilla chocolate /oa /ex
is related to how boolean variables are sorted. Currently in the version 2.0 released there is a bug in sorting of boolean 2x2 variables. The error will be fixed as soon as possible.
For numerical variables coded 1/0 or 2/1 there is no problem. The reason I did not catch the boolean Y/N error is, that the tab command gives correct estimates for boolean as well as numerical variables: tab ill cakes vanilla chocolate /oa /ex
But if the user adds the sorting (as was needed earlier) : tab ill cakes vanilla chocolate /oa /ex /sd reveals the bug.
The way development is done is that before release a number of tests are made, currently around 1250, e.g. after the mentioned tabulation 24 tests were applied for the tabulation of oswego rr values with different options (but not the /sd) option. The oswego rr test has now been extended to cover this issue as well. (18 more tests). A given test can be like this using result variables:
tab ill vanilla rolls /o
assert samenum(round($OR*100)/100,22.15) assert samenum(round($ORLL*100)/100,5.22) assert samenum(round($ORUL*100)/100,138.39)
assert samenum(round($OR1*100)/100,12.26) assert samenum(round($ORLL1*100)/100,1.76) assert samenum(round($ORUL1*100)/100,150.86)
assert samenum(round($OR2*100)/100,38.19) assert samenum(round($ORLL2*100)/100,4.06) assert samenum(round($ORUL2*100)/100,1983.85)
assert samenum(round($SumOR*100)/100,20.61) assert samenum(round($SumORLL*100)/100,4.93) assert samenum(round($SumORUL*100)/100,126.46)
The "hidden" bug arising by the sort option is a good example of why many tests are needed, but I think also that it shows that even with a number of test releases the policy of "silent release" is appropriate.
regards
The documented problems have been added to the versionfile on the epidata.dk site. I also uploaded a copy of the validation report after adding the sorting tests mentioned earlier today.
From now on validation reports will be uploaded regularly to the adress:
http://www.epidata.dk/documentation.php#tech
The actual test suite cannot be uploaded now, since some data material has been supplied from external sources. But a limited version will be uploaded at some point with publicly available data.
regards Jens Lauritsen
participants (1)
-
epidata-list@lists.umanitoba.ca