clustergrammer/src/zoom/zoom_rules_x.js

This is a clustergram implemented in D3.js. I started from the example http://bost.ocks.org/mike/miserables/ and added the following features

module.exports = function zoom_rules_x(viz, zoom_info){

  // zoom in the y direction before zooming in the x direction
  if (viz.zoom_switch > 1){
    if (zoom_info.zoom_x < viz.zoom_switch) {
      zoom_info.trans_x = 0;
      zoom_info.zoom_x = 1;
    } else {
      zoom_info.zoom_x = zoom_info.zoom_x / viz.zoom_switch;
    }
  }

  // calculate panning room available in the x direction
  zoom_info.pan_room_x = (zoom_info.zoom_x - 1) * viz.clust.dim.width;

  // console.log( 'pan_room_x: ' +  String(zoom_info.pan_room_x) + ' ' + String(-zoom_info.trans_x))

  // no positive panning or panning more than pan_room
  if (zoom_info.trans_x > 0) {
    zoom_info.trans_x = 0;
    // console.log('no positive panning\n\n')
  }
  else if (zoom_info.trans_x <= -zoom_info.pan_room_x) {
    zoom_info.trans_x = -zoom_info.pan_room_x;
    // console.log('restrict pan room\n\n')
  }


  return zoom_info;
};