I'm currently trying to draw charts with the help of SQL Anywhere's spatial data support and its SVG output methods. To combine several geometries into one document, I have to use the ST_AsSVG() method with the 'PathDataOnly=Yes' format specifier.

Now, when using ST_MultiPoint to draw sets of points, the according ST_AsSVG() method seems to deliver data for a SVG path element. While this works generally, when using a larger scale, the points are not visible as they are rendered by drawing a very narrow square (of 0.002 coordinates length).

So typically the method returns data like:

M 738,-2045 l 0.002,0 0,0.002 -0.002,0 Z
M 1365,-1432 l 0.002,0 0,0.002 -0.002,0 Z
M 2415,-1278 l 0.002,0 0,0.002 -0.002,0 Z
M 2460,-818 l 0.002,0 0,0.002 -0.002,0 Z
..

Obviously, the point coordinates are much larger (in my case, between 200 and 10,000) than the square dimensions.

When I manually modify the SVG data to use a larger square to draw, say by replacing "l 0.002,0 0,0.002 -0.002,0 Z" with "l 2,0 0,2 -2,0 Z", the points are drawn correctly.

Question: Is there a way (e.g. a format specifier) to adapt the square width for the ST_MultiPoint::ST_AsSVG() method?

For the moment, I have chosen to use single points instead of multipoints though this enlarged the SVG file significantly.

(For the record: Jason's blog article "SQL Graph Paper" was a great starting point - thanks!)