<svg id="svg" width="400" height="200" viewBox="0 0 200 200" style="border:1px solid #cd0000;">
    <rect x="10" y="10" width="150" height="150" fill="#cd0000"/>
</svg>
<p><input type="radio" id="radio0" name="ratio" value="" checked><label for="radio0">无preserveAspectRatio</label></p>
<p><input type="radio" id="radio1" name="ratio" value="meet"><label for="radio1">meet</label></p>
<p><input type="radio" id="radio2" name="ratio" value="slice"><label for="radio2">slice</label></p>
<p><input type="radio" id="radio3" name="ratio" value="none"><label for="radio3">none</label></p>

var svg = document.getElementById("svg");
svg && [].slice.call(document.querySelectorAll("input[type=radio]")).forEach(function(radio) {
    radio.addEventListener("click", function() {
        var value = this.value;
        if (value == "") {
            svg.removeAttribute("preserveAspectRatio");
            return;
        }
        if (value != "none") {
            value = "xMinYMin " + value;
        }
        svg.setAttribute("preserveAspectRatio", value);            
    });
});