MS RFC 29: Dynamic Charting Capability

[Daniel Morissette]

I've thought about this some more. It is probably not sufficient to 
provide the ability to lookup the chart size in an attribute, since this 
attribute may not be a value in pixels but would be an actual value 
(e.g. total amount of sales) so you really need to be able to define a 
range of sizes for the chart which is driven by an attribute.

We could be to keep PROCESSING CHART_SIZE as is, and define a second 
mechanism to specify the chart size:

  PROCESSING "CHART_SIZE_RANGE" "itemname minsize maxsize minval maxval"

where:

- itemname is the name of the attribute that drives the chart size (e.g. 
total_sales)

- minsize and maxsize are the minimum and maximum chart size values in 
pixels (e.g. "10 100")

- minval and maxval are the minimum values of the attribute that 
correspond to chart sizes of minsize and maxsize (e.g. 10000 1000000).

If the attribute value is smaller than 'minval' then the chart size will 
be minsize pixels, and if the attribute value is larger than maxval, the 
chart size will be maxsize pixels.


What would you think of that?

Daniel


Stephen Woodbridge wrote:
> Daniel Morissette wrote:
>> Stephen Woodbridge wrote:
>>>
>>> This looks like a nice addition. I think there would be some value to 
>>> supporting variable substitution in CHART_SIZE = [size]
>>>
>>> This would allow you to show the relative size of hits at a point and 
>>> have the chart show the percentage contributions in the wedges.
>>>
>>> for example total cars sold at a dealer, %ford, %gm, %honda, %nissan
>>>
>>
>> Um... that would be a nice feature, but currently attribute binding is 
>> for STYLE and LABEL only but not for PROCESSING directives, and I'm 
>> not sure that we want to start adding attribute binding everywhere 
>> either. I'd rather leave this one as a potential enhancement for a 
>> future release unless this is considered critical.
> 
> Critical, probably not, but a lot of the nice charts I have seen using 
> thematic pie charts do just that. May be it would be appropriate to move 
> size out of the processing directives and make it more like symbol size. 
> Yeah, I can see this is a tough one. Well I'll support whatever you 
> decide and if you go the extra mile on this I would be happy to owe you 
> a few extra cold and frosty ones :)
> 
> -Steve


-- 
Daniel Morissette
http://www.mapgears.com/