title: Rotate tree diagram on d3.js v5 (from horizental to vertical)
body: <p>I have the initial state of tree diagram that I'm building, with collapse animation and custom node design but whatever I try to make the tree vertical instead of horizontal I mess something else (animation not working well, the lines are wrong and other problems).</p>
  <p>I'm trying to visualize a merkle tree where a vertical display is more intuitive. unfortunately I dont have strong background in front-end or deep understanding of d3 lib.</p>
  <p>Here is the code:</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;!DOCTYPE html&gt;
  &lt;meta charset="UTF-8"&gt;
  &lt;style&gt;
      .node rect {
          stroke-width: 3px;
      }
      
      .node text {
          font: 12px sans-serif;
          fill: #fff;
      }
      
      .link {
          fill: none;
          stroke: #ccc;
          stroke-width: 2px;
      }
  &lt;/style&gt;
  
  &lt;body&gt;
  
      &lt;!-- load the d3.js library --&gt;
      &lt;script src="https://d3js.org/d3.v5.min.js"&gt;&lt;/script&gt;
      &lt;script&gt;
  
  var treeData =
    {
      "name": "NODE NAME 1",  
      "subname": "CODE N1",    
      "fill":"orange",
      "children": [
        { 
          "name": "NODE NAME 2.1",
          "subname": "CODE N1",    
          "fill":"blue"
        },
        { "name": "NODE NAME 2.2","subname": "CODE N1"  ,"fill":"blue" },
        { "name": "NODE NAME 2.3","subname": "CODE N1","fill":"blue",
        "children": [
            { "name": "NODE NAME 3.3","fill":"blue","subname": "CODE N1",
             "children": [{
                 "name":"NODE NAME 4.1","subname": "CODE N1",
                 "fill":"#d281d2"
             }
                 ] },
            { "name": "NODE NAME 3.4","fill":"blue", "subname": "CODE N1" ,
             "children": [{
                 "name":"NODE NAME 4.2", "subname": "CODE N1" ,
                 "fill":"#d281d2"
             }
                 ]
             }
          ]
          }
      ]
    };
  
  // Set the dimensions and margins of the diagram
  var margin = {top: 20, right: 90, bottom: 30, left: 90},
      width = 960 - margin.left - margin.right,
      height = 500 - margin.top - margin.bottom;
  
  // append the svg object to the body of the page
  // appends a 'group' element to 'svg'
  // moves the 'group' element to the top left margin
  var svg = d3.select("body").append("svg")
      .attr("width", width + margin.right + margin.left)
      .attr("height", height + margin.top + margin.bottom)
    .append("g")
      .attr("transform", "translate("
            + margin.left + "," + margin.top + ")");
  
  var i = 0,
      duration = 750,
      root;
  
  // declares a tree layout and assigns the size
  var treemap = d3.tree().size([height, width]);
  
  // Assigns parent, children, height, depth
  root = d3.hierarchy(treeData, function(d) { return d.children; });
  root.x0 = height / 2;
  root.y0 = 0;
  
  // Collapse after the second level
  root.children.forEach(collapse);
  
  update(root);
  
  // Collapse the node and all it's children
  function collapse(d) {
    if(d.children) {
      d._children = d.children
      d._children.forEach(collapse)
      d.children = null
    }
  }
  
  function update(source) {
  
    // Assigns the x and y position for the nodes
    var treeData = treemap(root);
  
    // Compute the new tree layout.
    var nodes = treeData.descendants(),
        links = treeData.descendants().slice(1);
  
    // Normalize for fixed-depth.
    nodes.forEach(function(d){ d.y = d.depth * 180});
  
    // ****************** Nodes section ***************************
  
    // Update the nodes...
    var node = svg.selectAll('g.node')
        .data(nodes, function(d) {return d.id || (d.id = ++i); });
  
    // Enter any new modes at the parent's previous position.
    var nodeEnter = node.enter().append('g')
        .attr('class', 'node')
        .attr("transform", function(d) {
          return "translate(" + source.y0 + "," + source.x0 + ")";
      })
      .on('click', click);
  
      var rectHeight = 60, rectWidth = 120;
      
      nodeEnter.append('rect')
        .attr('class', 'node')
        .attr("width", rectWidth)
        .attr("height", rectHeight)
        .attr("x", 0)
        .attr("y", (rectHeight/2)*-1)
        .attr("rx","5")
        .style("fill", function(d) {
            return d.data.fill;
        });
  
    // Add labels for the nodes
    nodeEnter.append('text')
        .attr("dy", "-.35em")
        .attr("x", function(d) {
          return 13;
        })
        .attr("text-anchor", function(d) {
          return "start";
        })
        .text(function(d) { return d.data.name; })
        .append("tspan")
        .attr("dy", "1.75em")
        .attr("x", function(d) {
          return 13;
        })
        .text(function(d) { return d.data.subname; });
  
    // UPDATE
    var nodeUpdate = nodeEnter.merge(node);
  
    // Transition to the proper position for the node
    nodeUpdate.transition()
      .duration(duration)
      .attr("transform", function(d) { 
          return "translate(" + d.y + "," + d.x + ")";
       });
  
    // Update the node attributes and style
    nodeUpdate.select('circle.node')
      .attr('r', 10)
      .style("fill", function(d) {
          return d._children ? "lightsteelblue" : "#fff";
      })
      .attr('cursor', 'pointer');
  
  
    // Remove any exiting nodes
    var nodeExit = node.exit().transition()
        .duration(duration)
        .attr("transform", function(d) {
            return "translate(" + source.y + "," + source.x + ")";
        })
        .remove();
  
    // On exit reduce the node circles size to 0
    nodeExit.select('circle')
      .attr('r', 1e-6);
  
    // On exit reduce the opacity of text labels
    nodeExit.select('text')
      .style('fill-opacity', 1e-6);
  
    // ****************** links section ***************************
  
    // Update the links...
    var link = svg.selectAll('path.link')
        .data(links, function(d) { return d.id; });
  
    // Enter any new links at the parent's previous position.
    var linkEnter = link.enter().insert('path', "g")
        .attr("class", "link")
        .attr('d', function(d){
          var o = {x: source.x0, y: source.y0}
          return diagonal(o, o)
        });
  
    // UPDATE
    var linkUpdate = linkEnter.merge(link);
  
    // Transition back to the parent element position
    linkUpdate.transition()
        .duration(duration)
        .attr('d', function(d){ return diagonal(d, d.parent) });
  
    // Remove any exiting links
    var linkExit = link.exit().transition()
        .duration(duration)
        .attr('d', function(d) {
          var o = {x: source.x, y: source.y}
          return diagonal(o, o)
        })
        .remove();
  
    // Store the old positions for transition.
    nodes.forEach(function(d){
      d.x0 = d.x;
      d.y0 = d.y;
    });
  
    // Creates a curved (diagonal) path from parent to the child nodes
    function diagonal(s, d) {
  
      path = `M ${s.y} ${s.x}
              C ${(s.y + d.y) / 2} ${s.x},
                ${(s.y + d.y) / 2} ${d.x},
                ${d.y} ${d.x}`
  
      return path
    }
  
    // Toggle children on click.
    function click(d) {
      if (d.children) {
          d._children = d.children;
          d.children = null;
        } else {
          d.children = d._children;
          d._children = null;
        }
      update(d);
    }
  }
  
  &lt;/script&gt;
  &lt;/body&gt;</code></pre>
  </div>
  </div>
  </p>