D3.js Set initial zoom level

Question

I have several graphs set up to zoom on the container and it works great. However, on the initial load, the zoom level is way too close. Is there a method of setting the initial zoom level to avoid having to first zoom out? I am familiar with the .scale() method but have not had any luck implementing it. Is this the way to go or is there something I am missing?

Here is what I have thus far as pertaining to zoom:

var margin = {top: 20, right: 120, bottom: 20, left: 120},     width = 50000 - margin.right - margin.left,     height = 120000 - margin.top - margin.bottom;  var x = d3.scale.linear()     .domain([0, width])     .range([0, width]);  var y = d3.scale.linear()     .domain([0, height])     .range([height, 0]);  var tree = d3.layout.tree()     .size([height, width])     .separation(function(a, b) { return (a.parent == b.parent ? 1 : 2) / a.depth; });  var diagonal = d3.svg.diagonal()     .projection(function(d) { return [d.x, d.y]; });  function zoom(d) {           svg.attr("transform",       "translate(" + d3.event.translate + ")"+ " scale(" + d3.event.scale + ")"); }  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 + ")")     .attr("pointer-events", "all")     .call(d3.behavior.zoom()         .x(x)         .y(y)         .scaleExtent([0,8])         .on("zoom", zoom))         .append('g');  svg.append('rect')     .attr('width', width*5)     .attr('height', height)     .attr('border-radius', '20')     .attr('fill', 'sienna'); 

Answer 1

D3v4 answer

If you are here looking for the same but with D3 v4,

var zoom = d3.zoom().on("zoom", function(){     svg.attr("transform", d3.event.transform); });  vis = svg.append("svg:svg")      .attr("width", width)      .attr("height", height)      .call(zoom) // here      .call(zoom.transform, d3.zoomIdentity.translate(100, 50).scale(0.5))      .append("svg:g")      .attr("transform","translate(100,50) scale(.5,.5)");