The currentScale property of the SVGSVGElement interface reflects the current scale factor relative to the initial view to take into account user magnification and panning operations on the outermost <svg> element.
DOM attributes currentScale and currentTranslate are equivalent to the 2×3 matrix [a b c d e f] = [currentScale 0 0 currentScale currentTranslate.x currentTranslate.y]. If "magnification" is enabled (i.e., zoomAndPan="magnify"), then the effect is as if an extra transformation were placed at the outermost level on the SVG document fragment (i.e., outside the outermost <svg> element).
If the <svg> element is not at the outermost level, then currentScale is always 1 and setting it has no effect.
A float.