Why can't I select SVG Polygon using Attribute[ID] ?

Why can't I select SVG Polygon using Attribute[ID] ?

I am trying some simple hover effects on some svg.
~ When i hover on a button the target SVG gets animated.
I am using Velocity,js for this project with jQuery.

For Button,
      <button data-targetX ="firstTra"></button>


This works,

      $('svg polygon[id="firstTra"]').velocity({opacity:1});

But this does not,
      
       var meinTarget = $(this).attr('data-targetX');                           //button's data attr
    
        $('svg polygon[id=meinTarget]').velocity({opacity:1});

      


However I am unable to use "data" attribute to target the same.
It just does not trigger anything.
Can some one help me...