Hi Andreas,
On Friday, 2007-03-09 14:36:03 -0700, Andreas J. Guelzow wrote:
> > > Furthermore, Ecma/Excel's definition of degrees of freedom looks weird,
> > > for rows>1 and cols>1 they say it would be (rows-1)*(cols-1). Why?!?
> >
> > Btw, OOo does the same. Probably because it was documented as such.
>
> Which test is CHITEST supposed to perform?
>
> In the cases of a test for independence or a test of homogeneity, these
> degrees of freedom make sense. (But we should have only one regular
> region).
It claims to be an independence test. On the other hand ...
> In the case of a Goodness-of-Fit test one would have observed and
> expected frequencies (corresponding to each other) and the degree of
> freedom should be n-1.
... it gets two arrays passed, one of actual/observed values and one of
expected values. See also the current definition in the latest draft
document uploaded on Friday. If each column of observed values would
represent a different group, matching those of the expected values, what
would n-1 be then? For example:
observed: x,y expected: X,Y =CHITEST(A1:B4;D1:E4)
| A B C D E
-+--------------
1| x y X Y
2| x y X Y
3| x y X Y
4| x y X Y
How would the (rows-1)*(cols-1) fit in there?
Eike
--
Automatic string conversions considered dangerous. They are the GOTO statements
of spreadsheets. --Robert Weir on the OpenDocument formula subcommittee's list.
