I think one approach would be to try and achieve a target number of
data points per horizontal pixels (I find somewhere between 15:1 and
6:1 pixels per data point a reasonable density/resolution).
The trick is that one may need to define the time resolution steps in
an even manner (i.e. going from second to minutes is a 60x reduction
in resolution, mins to hrs 60x, hrs to days 24x, days to wks 7x, wks
to mnths 4.3x, mnths to years 12x, yrs to decades, 10x). This would
take some thought to make sure the re-queries didn't chunk the data.
If I had the skills, I would re-query the data source based on the
required resolution. In Oracle SQL I often take the average of a
column of data and GROUP BY hour/day/month/year to get different
"resolutions" of data.
Just a thought.
Here's sample SQL code:
[code]
SELECT TO_CHAR(date_column, 'yyyy-mm') AS new_date_resolution,
-- change 'yyyy-mm' to 'yyyy' or 'yyyy-mm-dd' ....
ROUND(AVG(data_set_1),1),
ROUND(AVG(data_set_2),1),
ROUND(AVG(data_set_3),1)
FROM table_name
GROUP BY TO_CHAR(date_column, 'yyyy-mm') -- change 'yyyy-mm' to
'yyyy' or 'yyyy-mm-dd' ....
[/code]
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Google Visualization API" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/google-visualization-api?hl=en
-~----------~----~----~----~------~----~------~--~---
