我正在使用焦点+上下文图来显示历史数据。但这是非常不准确的。我上周每 10 分钟有一次数据。当数据不可用时,我希望可视化为空白。正如您在随附的屏幕截图中所见,我在周四 25 日至周五 26 日中午 12 点之间没有数据。但它仍然显示好像有数据。我可以只在数据存在的地方有颜色吗?
这可以通过焦点+上下文实现,还是我应该追求另一种形式的可视化?
这是我的代码:
function drawChart(user_name) {
var margin = {top: 10, right: 10, bottom: 100, left: 40},
margin2 = {top: 430, right: 10, bottom: 20, left: 40},
width = 960 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom,
height2 = 500 - margin2.top - margin2.bottom;
var parseDate = d3.time.format("%a %e %H %M").parse;
var x = d3.time.scale().range([0, width]),
x2 = d3.time.scale().range([0, width]),
y = d3.scale.linear().range([height, 0]),
y2 = d3.scale.linear().range([height2, 0]);
var xAxis = d3.svg.axis().scale(x).orient("bottom"),
xAxis2 = d3.svg.axis().scale(x2).orient("bottom"),
yAxis = d3.svg.axis().scale(y).orient("left");
var brush = d3.svg.brush()
.x(x2)
.on("brush", brushed);
var area = d3.svg.area()
.interpolate("monotone")
.x(function(d) { return x(d.receiveddate); })
.y0(height)
.y1(function(d) { return y(d.gtse); });
var area2 = d3.svg.area()
.interpolate("monotone")
.x(function(d) { return x2(d.receiveddate); })
.y0(height2)
.y1(function(d) { return y2(d.gtse); });
var svg = d3.select("body").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom);
svg.append("defs").append("clipPath")
.attr("id", "clip")
.append("rect")
.attr("width", width)
.attr("height", height);
var focus = svg.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
var context = svg.append("g")
.attr("transform", "translate(" + margin2.left + "," + margin2.top + ")");
d3.json("rest.php/lastweek"+"/"+user_name, function(error, data) {
var allData = data.records;
var gtsef = [];
allData.forEach(function(d) {
var formattedDate = new Date(+d.receiveddate).toString();
d.receiveddate = parseDate(d3.time.format("%a %e %H %M")(new Date(formattedDate)));
d.gtse = +d.gtse;
gtsef.push(d.gtse);
});
x.domain(d3.extent(allData.map(function(d) { return d.receiveddate; })));
y.domain([0, d3.max(allData.map(function(d) { return d.gtse; }))]);
x2.domain(x.domain());
y2.domain(y.domain());
focus.append("path")
.datum(data.records)
.attr("clip-path", "url(#clip)")
.attr("d", area);
focus.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
focus.append("g")
.attr("class", "y axis")
.call(yAxis);
context.append("path")
.datum(data.records)
.attr("d", area2);
context.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height2 + ")")
.call(xAxis2);
context.append("g")
.attr("class", "x brush")
.call(brush)
.selectAll("rect")
.attr("y", -6)
.attr("height", height2 + 7);
});
function brushed() {
x.domain(brush.empty() ? x2.domain() : brush.extent());
focus.select("path").attr("d", area);
focus.select(".x.axis").call(xAxis);
}
}