Re: [office] surface plots

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

On Thu, 2009-07-30 at 23:03 +0200, Eike Rathke wrote:

> >
> > Gnumeric has various ways this could be specified. Gnumeric implements
> > chart:surface as a contour plot (not an xyz contour plot), So data would
> > look like:
> >
> >   A  B  C  D  E
> > 1 -- 1  2  3  4
> > 2 1  2  7  5  6
> > 3 2  4  3  3  2
> > 4 3  5  6  5  4
> > 5 4  3  2  3  2
> > 6 5  4  5  5  5
> >
> > The "y"-values would be the range B2:E6, the "x" values would be given
> > by B1:E1 and the "z"-values as A2:A5. So the height at x=3 z=2 would be
> > 6.
> >   
> The ODF 1.0 description says:
> "The data points are interpreted as tabular data, where each value 
> defines a 'height'
> at a specific grid location."
> There is nothing said, that some values are interpreted as x values, 
> some as y and some as height. It says *each value defines a 'height'*. 
> So I don't see how your interpretation could fit into that description.

The series would give a range of B2:E6 so all those data points are in
fact heights. 

> > The same would be true for gnumeric's surface plots.
> >
> > THe description you gave above is gnumeric's xyz contour and xyz surface
> > plots.
> >   
> Well nice! Come up with a proposal for a new value for attribute 
> chart:class to describe your xyz-surfaces and contours!
> >   
> >> Furthermore this would allow for not equidistant points 'on the grid' 
> >> what is not wanted for the surface chart.
> >>     
> >
> > Why not? 
> >   
> Because this was not specified.

Perhaps I missed it but where were the equidistant points specified ?

> >   
> >>>> In case of chart:three-dimensional="false" each altitude value is 
> >>>> located on a Cartesian x-/y-grid.
> >>>> In case multiple series with type surface are given the accessory x and 
> >>>> y coordinates are determined as follows.
> >>>> The x-coordinates are generated from the positions in the altitude-value 
> >>>> sequence starting with 1.0. The
> >>>> y-coordinates are generated from the positions of the series elements 
> >>>> starting with 1.0.
> >>>> In case only one series with type surface is given the accessory x and y 
> >>>> coordinates are determined as follows.
> >>>> ... please enter a suggestion to describe how the x and y values are 
> >>>> determined in this case ...
> >>>> ----------------------
> >>>>     
> >>>>         
> >>> Considering your description, how could you ever obtain the
> >>> chart:surface image given in ODF 1.1 (note that the vertical axis does
> >>> not have numerical values).
> >>>   
> >>>       
> >> The surface image given in ODF 1.1 can be obtained using the multi 
> >> series approach and taking the series names as labels for the axis.
> >> Use this cell values in range A1:C4 :
> >> 1    2   3
> >> 2    4   6
> >> 3    6   9
> >> 4    8   12
> >> And 3 series:
> >> series1 with value range A1:A4 (and name R1)
> >> series2 with value range B1:B4 (and name R2)
> >> series3 with value range C1:C4 (and name R3)
> >>
> >> You can create it in this way for example in Excel. Furthermore Gnumeric 
> >> does import such an Excel surface chart from xls properly.
> >>     
> >>> How would you specify the x and z (?) values if they were not simply 1
> >>> through n?
> >>>   
> >>>       
> >> I don't understand this. Your suggestion was not to have values 1 
> >> through n but values from cell ranges, wasn't it?
> >>     
> >>> Are we even talkning about the same _2_-dimensional charts?
> >>>   
> >>>       
> >> I tried Gnumeric 1.9.10 and found that charts were not saved at all when 
> >> saving to ODF format. So if Gnumeric has not produced files containing 
> >> surface charts I see no reason why the specification should be made 
> >> extra complicated here.
> >>     
> >
> > These plots are implemented in Gnumeric 1.9.11.
> >   
> That version is not offered for download at the Gnumeric side, so there 
> is no problem with created files.

Users have public access to our development code and lots of users are
in fact using it. (In fact 1.9.10 will export those charts too. I assume
you used the misnumbered Windows Version on The Gnumeric web site.) And
I doubt that ODF 1.2 will be approved before the next releases of
Gnumeric. 

I did send a proposed clarification for chart:surface to the list.

Andreas


-- 
Andreas J. Guelzow <aguelzow@pyrshep.ca>