Re: gnumeric XML doesn't show result of formula

["Andreas J. Guelzow" <aguelzow pyrshep ca>]

On Sun, 2008-02-03 at 07:22 +1100, John Machin wrote:
> Andreas J. Guelzow wrote:
> > On Sat, 2008-02-02 at 12:55 +1100, John Machin wrote:
> >   
> > > Hello,
> > > Here's the results of a little experiment (start up the UI, type 
> > > =sqrt(2) into cell A1, save as ...) for a few varieties of XML 
> > > spreadsheet file formats:
> > >
> > > [my comments in [], whitespace adjusted by me]
> > >
> > > Excel 2007 .xlsx file:
> > > <c r="A1">
> > >     <f>SQRT(2)</f>
> > >     <v>1.4142135623730951</v> [OK]
> > > </c>
> > >
> > > Excel 2003 "Save as XML Spreadsheet":
> > > <Cell ss:Formula="=SQRT(2)">
> > >     <Data ss:Type="Number">1.4142135623730951</Data> [OK]
> > > </Cell>
> > >
> > > OpenOffice.org Calc 2.x .ods file:
> > > <table:table-cell table:formula="oooc:=SQRT(2)" 
> > > office:value-type="float" office:value="1.4142135623731"> [only 14 
> > > digits of precision]
> > >     <text:p>1.41</text:p>
> > > </table:table-cell>
> > >
> > > Gnumeric [1.6.3, Windows] .gnumeric file:
> > > <gnm:Cell Col="0" Row="0">=sqrt(2)</gnm:Cell> [no result at all]
> > >
> > > Bug or feature? Is it fixed in the 1.8.1 release?
> > >     
> >
> > I don't see a bug or feature...
> >
> > Excel 2007, 2003 and OO 2.x appear to give 2 values for each cell (and
> > those values are even the same since none of the given floating point
> > values are equal to the square root of 2.)
> >
> > So Gnumeric is more consistent by giving just one value.
> >
> >   
> I think that what you are trying to say is that it is impossible to 
> represent the square root of 2 exactly as a floating-point number. This 
> is true/well-known/irrelevant. What is of *practical* interest is the 
> actual FP result of evaluation of any formula, irrespective of whether 
> the result can be represented exactly or not. The two Excel outputs give 
> in this case what appears to be the nearest possible FP result.  OO 2.x 
> records an inaccurate result. Gnumeric gives *ZERO* results.

You are comparing apples and oranges:  

Gnumeric's xml file contains all information necessary to obtain the
values you are looking for, you apparently would liek to have the value
also stored. This is completely useless for the majority of users. 

I doubt that you would be able to find those values easily in Excel's
default file format either. Interestingly enough there you chose a file
format that happens to include those values. You could have also chosen
such a format for Gnumeric. For example any text export can include any
number of digits you may desire. Or you could export as an OpenDocument
file which would also include both formulas and values if you prefer an
xml format. But you probably wouldn't be happy with the number of digits
provided:
          <table:table-cell table:formula="oooc:=sqrt(2)"
office:value-type="float" office:value="1.414213562">
            <text:p>1.4142135623731</text:p>
          </table:table-cell>

Andreas


>
-- 
"Liberty consists less in acting according to
one's own pleasure, than in not being subject 
to the will and pleasure of other people. It 
consists also in our not subjecting the wills 
of other people to our own."  Rousseau

Andreas J. Guelzow
Pyrenean Shepherds