XML Elves

hello everyone,

Can anyone tell me how the matrix works? i am using a matrix to transform the geographic y into svg.
ex: transform="matrix(1 0 0 -1 0 293156.21565)". I woould like to know how to calculate the last number.

Thanks in nadvance,sebastien.

Suppose that your geographic coordinates go from 0 to Xmax and 0 to Ymax, you can use
matrix(1 0 0 -1 0 -Ymax) to get your map in svg

If coordinates don't start from 0 but from Ymin for y, you have to use
matric(1 0 0 -1 0 Ymin - Ymax)

Michel

PS Suppose that viewBox is Xmin Ymin Xmax - Xmin Ymax - Ymin or that there is no attribute viewBox ...

Thanks Michel,

actually i am using another formula, it seems to work but i might be wrong. Tell me what you think about it.

viewbox=" xmin ymin width height"
mat6=(ymin*2+heigth)
transforme="matrix(1 0 0 -1 0 mat6");

sebastien

These formula

transforme="matrix(1 0 0 -1 0 mat6");

seem good and surely better than I write .....

Michel

Good i am getting better...

A plus,sebastien.