chart:column-mapping, chart:row-mapping

[Patrick Durusau <patrick@durusau.net>]

Greetings!

By way of background, these attributes provide list of indexes of data 
series for display as charts. If present (only one of them can be 
present for any given chart) then varying the order of the indexes will 
vary the presentation of the data series in the chart.

Some questions:

1) How are the indices assigned to the rows or columns? That is to say, 
how do I know what index has been assigned to a data series?

Note that the <chart:series> element that represents a data series in a 
chart does not have an attribute that would serve to hold that index 
number. (The attributes of <chart:series> being:

    *

      |chart:attached-axis|

    *

      |chart:class|

    *

      |chart:label-cell-address|

    *

      |chart:style-name|

    *

      |chart:values-cell-range-address|

||2) Do we need both column and row mapping attributes for this purpose?

Consider the current language (which I am splitting apart to define 
these separately):

> The |chart:column-mapping| and |chart:row-mapping| attributes contain, 
> if provided, a list of indexes of series. The numbers define a 
> reordering of data that comes from a container document that provides 
> the data for the chart. The numbering begins with 1. A list of 
> ascending numbers beginning with 1 has no effect. To exchange two 
> series, their numbers must be exchanged in the list.
>
> The |chart:column-mapping| and |chart:row-mapping| attributes must not 
> be used simultaneously.
>
That doesn't seem to me to work with the definition of 
chart:values-cell-range-address, which is defined as 
cellRangeAddressList, which is defined as:

<define name="cellRangeAddressList">
    <!-- Value is a space separated list of "cellRangeAddress" patterns -->
    <data type="string"/>
</define>
||

|So, for each chart:values-cell-range-address value may itself be a list 
of cellRangeAddress values.
|

|As a matter of practice it may be that for some charts applications do 
limit the choices to rows or columns but we don't have that restriction 
in the current draft. Nor do we apparently have any place to locate the 
indexes.
|

|My question is how do we index inside an arbitrary list of 
"cellRangeAddress" patterns?
|

|We can assign each pattern an index number and force it to be unique, 
but how do we establish the order? Which column/row comes first? Or is 
that set by the user? Where is the mapping of the index stored?
|

|Hmmm, I suppose we need to define what we mean by a series? Yes?
|

|Moreover, I don't think allowing multiple series to have the same index 
number, said to be 1 above, really makes much sense.
|

|I don't have any real preference on these issues but I do think we need 
to sort them out for 1.2.
|

The question that started my down this path this morning was quite simple:

3) Are these meaningful attributes when used with circle and ring 
graphs? ;-)

See how things can unravel on you?

I don't think they are meaningful in any event with a circle graph. 
(Unless we want to allow the user to specify the placement of segments 
around the pie, then it would be meaningful.) Why we didn't say "pie" 
graph I don't know. [Search counts: "circle graph" 45,700, "pie graph" 
136,000, "circle chart" 767,000, "pie chart" 2,390,000]

With a ring graph (I am still working on a definition) I think we need 
to defined the "default order" of a ring graph versus the order of an 
index of data series.

It may seem "obvious" that it starts at the center and proceeds outward 
but I think we need to say that and bind the index of any date series to 
that interpretation.

I am going to work on adding more reference points just to take a break 
from the attributes on charts. ;-)

Hope everyone is having a great day!

Patrick
||

|
|

-- 
Patrick Durusau
patrick@durusau.net
Chair, V1 - US TAG to JTC 1/SC 34
Convener, JTC 1/SC 34/WG 3 (Topic Maps)
Editor, OpenDocument Format TC (OASIS), Project Editor ISO/IEC 26300
Co-Editor, ISO/IEC 13250-1, 13250-5 (Topic Maps)