3
我已經實現了一個d3線圖，它從CSV文件中讀取數據，然後繪製對mouseover事件作出反應的多行。它工作正常使用下面的代碼（抱歉，這是這麼久，稍有凌亂，但我覺得最好還是顯示完整的代碼）的平移和縮放：帶有限變焦的d3圖形
d3.csv("ijisb.csv", function(error, data) {
var margin = {top: 50, right: 120, bottom: 50, left: 70},
width = 1200 - margin.left - margin.right,
height = 800 - margin.top - margin.bottom;
var parseDate = d3.time.format("%m%d").parse;
var color = d3.scale.category20();
color.domain(d3.keys(data[0]).filter(function(key) { return key !== "date"; }));
data.forEach(function(d) {
d.date = parseDate(d.date);
});
var sources = color.domain().map(function(name) {
return {
name: name,
values: data.map(function(d) {
return {date: d.date, temperature: +d[name]};
})
};
});
var x = d3.time.scale()
.range([0, width])
.domain([
d3.min(data, function(d) { return d.date; }),
d3.max(data, function(d) { return d.date; })
]);
var y = d3.scale.linear()
.range([height, 0])
.domain([
0,
d3.max(sources, function(c) { return d3.max(c.values, function(v) { return v.temperature; }); })
]);
var xAxis = d3.svg.axis()
.scale(x)
.orient("bottom")
.ticks(12)
.tickFormat(d3.time.format("%b %d"));
var yAxis = d3.svg.axis()
.scale(y)
.orient("left")
.ticks(5);
var line = d3.svg.line()
.defined(function(d) { return d.temperature >= 0; })
.x(function(d) { return x(d.date); })
.y(function(d) { return y(d.temperature); });
var zoom = d3.behavior.zoom()
.x(x)
.y(y)
.scaleExtent([1, 8])
.on("zoom", zoomed);
var svg = d3.select("body").append("svg")
.attr("width", "100%")
.attr("height", "100%")
.attr("viewBox", "0 0 1200 800")
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")")
.call(zoom);
var rect = svg.append("svg:rect")
.attr("width", width)
.attr("height", height)
.attr("class", "plot");
var make_x_axis = function() {
return d3.svg.axis()
.scale(x)
.orient("bottom")
.ticks(12)
.tickFormat(d3.time.format("%b %d"));
};
var make_y_axis = function() {
return d3.svg.axis()
.scale(y)
.orient("left")
.ticks(5);
};
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
svg.append("g")
.attr("class", "y axis")
.call(yAxis);
svg.append("g")
.attr("class", "x grid")
.attr("transform", "translate(0," + height + ")")
.call(make_x_axis()
.tickSize(-height, 0, 0)
.tickFormat(""));
svg.append("g")
.attr("class", "y grid")
.call(make_y_axis()
.tickSize(-width, 0, 0)
.tickFormat(""));
var source = svg.selectAll(".source")
.data(sources)
.enter().append("g")
.attr("class", "source");
var clip = svg.append("clipPath")
.attr("id", "clip")
.append("rect")
.attr("x", 0)
.attr("y", 0)
.attr("width", width)
.attr("height", height)
.append("text");
source.append("path")
.data(sources)
.attr("class", "line")
.attr("clip-path", "url(#clip)")
.attr("d", function(d) { return line(d.values); })
.style("stroke", function(d) {return color(d.name);})
.style("opacity", 0.8)
.on("mouseover", function(d){
d3.select(this)
.style("stroke",function(d) {return color(d.name);})
.style("opacity", 1.0)
.style("stroke-width", 2.5);
this.parentNode.parentNode.appendChild(this.parentNode);
d3.select('#text-' + d.name)
.style("fill",function(d) {return color(d.name);})
.style("font-weight", 700);
})
.on("mouseout", function(d) {
d3.select(this)
.transition()
.duration(250)
.style("stroke", function(d) {return color(d.name);})
.style("stroke-width", 1.5)
.style("opacity", 0.8);
d3.select('#text-' + d.name)
.transition()
.duration(250)
.style("fill", function(d) {return color(d.name);})
.style("font-weight", 400);
})
.attr("id", function(d, i) { return "path-" + d.name; });
source.append("text")
.datum(function(d) { return {name: d.name}; })
.attr("x", function(d, i) { return width+10; })
.attr("y", function(d, i) { return (i*(height/16)); })
.style("fill", function(d) {return color(d.name);})
.on("mouseover", function(d){
d3.select('#path-' + d.name)
.style("stroke",function(d) {return color(d.name);})
.style("opacity", 1.0)
.style("stroke-width", 2.5);
this.parentNode.parentNode.appendChild(this.parentNode);
d3.select(this)
.style("fill",function(d) {return color(d.name);})
.style("font-weight", 700);
})
.on("mouseout", function(d) {
d3.select('#path-' + d.name)
.transition()
.duration(250)
.style("stroke", function(d) {return color(d.name);})
.style("stroke-width", 1.5)
.style("opacity", 0.8);
d3.select(this)
.transition()
.duration(250)
.style("fill", function(d) {return color(d.name);})
.style("font-weight", 400);
})
.text(function(d) { return d.name; })
.attr("font-family","sans-serif")
.attr("font-size","14px")
.attr("id", function(d, i) { return "text-" + d.name; }
);
var minT = new Date('01/01/1900'), maxT = new Date('01/01/2002'), w = $(window).width();
function zoomed() {
d3.event.translate;
d3.event.scale;
svg.select(".x.axis")
.call(xAxis);
svg.select(".y.axis").call(yAxis);
svg.select(".x.grid")
.call(make_x_axis()
.tickSize(-height, 0, 0)
.tickFormat(""));
svg.select(".y.grid")
.call(make_y_axis()
.tickSize(-width, 0, 0)
.tickFormat(""));
source.select(".line")
.attr("d", function(d) { return line(d.values); })
.style("stroke", function(d) {return color(d.name);});
}
});
我的問題是，我想限制平移和縮放，以便圖形無法放大或平移離屏。我可以通過設置scaleExtent上的變焦（在上面的例子中實現）和改變縮放函數來做到這一點：
function zoomed() {
var t = zoom.translate(),
tx = t[0];
ty = t[1];
tx = Math.min(tx, 0);
zoom.translate([tx, ty]);
d3.event.translate;
d3.event.scale;
svg.select(".x.axis")
.call(xAxis);
svg.select(".y.axis").call(yAxis);
svg.select(".x.grid")
.call(make_x_axis()
.tickSize(-height, 0, 0)
.tickFormat(""));
svg.select(".y.grid")
.call(make_y_axis()
.tickSize(-width, 0, 0)
.tickFormat(""));
source.select(".line")
.attr("d", function(d) { return line(d.values); })
.style("stroke", function(d) {return color(d.name);});
}
這限制了x軸的最小爲零。然而，儘管我努力嘗試，但我無法限制x軸的最大值，這意味着圖形仍然可能偏移太遠。
任何幫助？我希望這是有道理的！
尼克