javascript - D3.js: Wrong position of horizontal and vertical focus lines (crosshairs) in line chart -

i adapted example data: d3js graph x , y crosshairs, , threshold line.

it works pretty good, lines not shown on right point. see screenshot.

i think there problem domain, can't figure out. here script:

update: problem caused way position text. ideas how position text in way?

var svg = d3.select("svg"),         margin = {top: 20, right: 50, bottom: 30, left: 50},         width = +svg.attr("width") - margin.left - margin.right,         height = +svg.attr("height") - margin.top - margin.bottom,         g = svg.append("g").attr("transform", "translate(" + margin.left + "," + margin.top + ")");  var parsetime = d3.utcparse("%y-%m-%dt%h:%m:%s.%lz"); var bisectdate = d3.bisector(function(d) { return d.timestamp; }).left; var formatvalue = d3.format(",.2f");   d3.json("data.json", function(error, json) {     if (error) throw error;     var data = json[0].tidedata;     data.foreach(function(d) {         d.timestamp = parsetime(d.timestamp);     });      var xdomain = d3.extent(data, function(d) { return d.timestamp; });     var ydomain = d3.extent(data, function(d) { return d.tide; });      var xscale =  d3.scaletime().rangeround([0, width]).domain(xdomain);     var yscale = d3.scalelinear().rangeround([height, 0]).domain(ydomain);      var line = d3.line()             .defined(function(d) { return d.tide!=null; })             .x(function(d) { return xscale(d.timestamp); })             .y(function(d) { return yscale(d.tide); });      g.append("g")             .attr("class", "axis axis--x")             .attr("transform", "translate(0," + height + ")")             .call(d3.axisbottom(xscale));      g.append("g")             .attr("class", "axis axis--y")             .call(d3.axisleft(yscale))             .append("text")             .attr("fill", "#000")             .attr("transform", "rotate(-90)")             .attr("y", 6)             .attr("dy", "0.71em")             .style("text-anchor", "end")             .text("sea level");      g.append("path")             .datum(data)             .attr("class", "line")             .attr("d", line);      var focus = g.append("g")             .attr("class", "focus")             .style("display", "none");      focus.append("circle")             .attr("r", 4.5);      focus.append("text")             .attr("x", 9)             .attr("dy", ".35em");      focus.append('line')             .attr('id', 'focuslinex')             .attr('class', 'focusline');      focus.append('line')             .attr('id', 'focusliney')             .attr('class', 'focusline');      g.append("rect")             .attr("class", "overlay")             .attr("width", width)             .attr("height", height)             .on("mouseover", function() { focus.style("display", null); })             .on("mouseout", function() { focus.style("display", "none"); })             .on("mousemove", mousemove);      function mousemove() {         var mouse = d3.mouse(this);         var mousedate = xscale.invert(mouse[0]);         var = bisectdate(data, mousedate); // returns index current data item          var d0 = data[i - 1];         var d1 = data[i];         // work out date value closest mouse         var d = mousedate - d0[0] > d1[0] - mousedate ? d1 : d0;          var x = xscale(d.timestamp);         var y = yscale(d.tide);          focus.attr("transform", "translate(" + x + "," + y + ")");         focus.select("text").text(formatvalue(d.tide));         focus.select('#focuslinex')                 .attr('x1', x).attr('y1', yscale(ydomain[0]))                 .attr('x2', x).attr('y2', yscale(ydomain[1]));         focus.select('#focusliney')                 .attr('x1', xscale(xdomain[0])).attr('y1', y)                 .attr('x2', xscale(xdomain[1])).attr('y2', y);      } }); 

in code creating focus lines, using current data point(mouse position) start lines.

    focus.select('#focuslinex')             .attr('x1', x).attr('y1', yscale(ydomain[0]))             .attr('x2', x).attr('y2', yscale(ydomain[1]));     focus.select('#focusliney')             .attr('x1', xscale(xdomain[0])).attr('y1', y)             .attr('x2', xscale(xdomain[1])).attr('y2', y); 

you horizontal line should start y axis , span on width @ hight of point. vertical line should start @ top of graph , go till bottom(x axis).

try change

   focus.select('#focuslinex')             .attr('x1', x).attr('y1', 0)             .attr('x2', x).attr('y2', heightofchart);     focus.select('#focusliney')             .attr('x1', 0).attr('y1', y)             .attr('x2', widthofchart).attr('y2', y); 

hope helps