The view box parameter allows you to set the part of the canvas you want to see/display.
If you want to "resize" your svg (an svg has no real size, because it is a vector image), you can add/change the parameters width and height present in the <svg>
header like this :
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" contentScriptType="text/ecmascript" zoomAndPan="magnify" width="1200" height="720" contentStyleType="tex ....</svg>
If you want to change the view box, you can add the parameter
viewBox="0 0 1200.0 720.0"
in the <svg>
header (for a HD view of 1200 by 720).