10-29-2006 11:04 AM
10-29-2006 12:29 PM - edited 10-29-2006 12:29 PM
Sorry, I never used this function and I am not familiar with the math.
@DonRoth wrote:
It is also not possible it seems to get into the Wilcoxon function diagram while running the overall code since when one selects the pair-samples polymorphic instance, the function front panel and diagram do not indicate running.
I have no problem opening the diagram, see it running if the calling program is running, and see all values appear on its front panel, and even place working probes deep inside subVIs. (Make sure you are opening the right instance: First select the polymorphic instance, then open the front panel).
@DonRoth wrote:
Another issue that I have seen is that changing the signficance level to 0.1 from 0.05 would change the p-value, but then changing it back to 0.05 did not change it back to the original p-value.
I cannot find anything in the function code that would cause this (e.g. no uninitialized shift registers, etc.) All code is pretty linear and deterministic. Make sure you are reading the new value from a terminal within the event structure, else you might get a stale value for p.
Can you make a small demo containing some sample data that shows the behavior?
Message Edited by altenbach on 10-29-2006 10:31 AM
10-30-2006 08:50 AM
10-30-2006 08:52 AM
10-30-2006 06:18 PM - edited 10-30-2006 06:18 PM
Message Edited by Chris_C. on 10-30-2006 06:19 PM
Message Edited by Chris_C. on 10-30-2006 06:19 PM
10-31-2006 08:09 AM
Yesterday I just threw together a quick example with no regard for proper programming style and in my haste interchanged sample sets X and Y in the two different instances of the Wilcoxon Signed Rank Test in the Wilcoxon_test.VI. (In fact this was the problem in my original code as well). This example should be easier to follow and just sends you directly back to the "Distribution Statistics Boolean" case after changing the Significance Level, so that only one instance executes.
Digging deeper into the NI_Gmath.lvlib:st_Wilcoxon diff test.vi block diagram, we can see that 'p-value' should not depend on the signficance level, it is only dependent on calculation from 'Normal CDF.vi'. Only the 'Reject Null Hypothesis' will be dependent upon the relationship between significance level and p-value. Therefore, to make a long story short, I believe it was my mistake in interchanging sample sets between the two instances of the Wilcoxon Signed Rank Test function that caused my confusion (and probably yours). I do now think the Wilcoxon code is executing correctly, although I will look into validation against statistical tables.
Sorry for taking your time on this one - just could not see the obvious until I put it down for 24 hours and looked at it again.
Sincerely,
Don