More on chart:class (different issue)

[Patrick Durusau <patrick@durusau.net>]

Greetings!

When looking at the chart:class attribute that specifies the "type" of a 
chart we find:

    *

      |line| – the data points of each data series are connected through
      lines.

    *

      |area| – the area below a data series is filled, and additional
      data series are stacked.

etc.

And the notation that all these values are prepended with a namespace. 
If you want additional types, then supply another namespace.

We also say that types can be further specified by adding more 
formatting properties.

Actually, what is being described both by the "type" and by the 
additional formatting properties is the formating for a chart. One 
assumes the data/input to the chart is the same and all that varies is 
the presentation of that data.

First issue:

If that is the case, then we really need to define more precisely what 
is meant for each of the "types" as we use the term for this attribute. 
The definition: "the area below a data series is filled, and additional 
data series are stacked" is rather imprecise.

Contrast that with:

****
An area graph is drawn on an X-Y grid and the area between the line and 
the X-axis is usually a different color from the area above the line. By 
default, each data set is drawn as a percentage of the sum of all the 
data sets represented.

Note: This is also known as a "stacked" area graph.
****

I rather shamelessly reworded all that from: 
http://www.graphicsserver.com/com_products/GraphChoiceArea.aspx

Do note it wasn't necessary to use a graphic or example to clearly 
express what was being defined.

We don't by default support absolute or stacked percentage graphs.

***************************************************

Second issue:

We say that with a namespace that other graph types can be specified.

OK, how does that impact interoperability?

Should we require (*must*) the inclusion of a rendered version of a 
graph when a document is saved? It would not be updated by an 
application that does not support a particular graph type but at least 
it could be displayed.

If an application can only display a graph, should it have some required 
text to display? Such as "Stored Rendering, May Not Be Current"?

That seems a bit verbose to me but I do think we need to have a standard 
signal that updated information is not being conveyed by the document 
plus the current application.

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)