Aha, thanks to sas who pointed out that svg operates in windows dos space where y-axis grows down I figured it out (I think). The question is where does it grow down from -- ans from the top edge of the page. Hence the mapping from svg space to inkspace space is quite simple and do-able. (I think) T...

Thanks for the help. It is really helpful.

This sorta suggests that one cannot use 3 and 4 quadrants when using SVG with inkscape
-- keeping track of the transforms would be horrendous. Too bad -- manipulating an image with its XML representation is very attractive.

When trying to find a work-around to the scaling problem I tried to place a rectangle in each of the 4 quadrants. No problem manually. With XML when I place a rectangle at: id="rect2382" width="30" height="10" x="10" y="-20" /> it came out on the scr...

I made a rectangle x-orig 1.515 y-orig 7.528 Width 51.248 Height 25.913 Using Object -> Transform -> Scale I doubled the rectangle and got x-orig -24.109 wrong y-orig -5.428 wrong Width 102.495 correct Height 51.826 correct Using Object -> Transform -> Matrix I doubled the rectangle and got x-orig 3...

I parse inkscape XML to automate rescaling of imagines. The transform from a manually derived (i.e., mouse and keyboard) gives the XML transform="matrix(1.5,0,0,1.5,-28.57142,-1440.0)"> makes the image 50% larger -- i.e., 1.5, 0 , 0 ,1.5 The last two values are tx, ty translate values. I c...