D3 Fixed Max Scale

Done as an anser to http://stackoverflow.com/questions/14840759/how-to-set-the-domain-and-scale-on-an-yaxis-on-a-discretebarchart-nvd3-js

HTML

<script src="http://d3js.org/d3.v3.min.js"></script>
<html>
    <body>
        <div id="chart"></div>
    </body>
</html>

CSS

body {
  font: 10px sans-serif;
}

svg {
    background:whitesmoke;
}
.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.bar {
  fill: steelblue;
}

.x.axis path {
  display: none;
}

JavaScript

var margin=40;
var width = 600-margin*2, height=600-margin*2;

var svg = d3.select("#chart").append("svg")
    .attr("width", width + margin*2 + "px")
    .attr("height", height + margin*2 + "px")
    .append("g")
        .attr("transform", "translate(" + margin + ", " + margin + ")");

var xScale = d3.scale.ordinal()
    .rangeRoundBands([0, width], .1);
var yScale = d3.scale.linear()
    .range([height, -40]);

var xAxis = d3.svg.axis()
    .scale(xScale)
    .orient("bottom");
var yAxis = d3.svg.axis()
    .scale(yScale)
    .orient("left");

var data = [
    {l: 'a', v: -111},
    {l: 'b', v: 222},
    {l: 'c', v: 333}
];

xScale.domain(data.map(function (d) { return d.l; } ));
//yScale.domain([0, d3.max(data, function (d) { return d.v; }) ]);
yScale.domain([0, 400]);

svg.append("g")
    .attr("class", "x axis")
    .attr("transform", "translate(0," + height + ")")
    .call(xAxis);

svg.append("g")
    .attr("class", "y axis")
    .call(yAxis);

svg.selectAll("rect").data(data).enter()
    .append("rect")
    .attr("class", "bar")
    .attr("x", function(d) { return xScale(d.l); })
    .attr("width", xScale.rangeBand())
    .attr("y", function(d) { return yScale(d.v); })
    .attr("height", function(d) { return height - yScale(d.v); });