我有像这样的.svg文件
<?xml version="1.0" encoding="utf-8"?>
<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" width="994px"
height="1415px" viewBox="0 0 994 1415" enable-background="new 0 0 994 1415" xml:space="preserve">
<g id="red_purple">
<g>
<polygon id="L249" fill="#99637E" points="654.5,400.5 654.5,346.5 691.5,346.5 691.5,368.5 711.5,368.5 711.5,400.5 "/>
<path fill="#7C6091" d="M691,347v21v1h1h19v31h-56v-53H691 M692,346h-38v55h58v-33h-20V346L692,346z"/>
</g>
</g>
我需要多边形中的位置X和Y,我该怎么做?