我是d3.js的新手,如果这听起来像是一个幼稚的问题,请原谅我。我绘制了一条线(d3 v4),可以通过其端点拖动。终点是矩形。
当前输出如下:
我面临的挑战是-当我开始拖动该点时,该线似乎是从左上角开始的。当我拖动同一条线的第二点时,该线将按预期方式拖动/移动。
示例数据如下:
要求您提供有关如何解决上述问题的建议/意见。
下面是我正在使用的附件代码:
var margin = { top: 0, right: 0, bottom: 0, left: 0 },
width = +svg.attr("width") - margin.left - margin.right,
height = +svg.attr("height") - margin.top - margin.bottom;
// Creating the colour Category
var color = d3.scaleOrdinal(d3.schemeCategory10);
var y = d3.scaleLinear().range([390, 0]);
// Scale the range of the data
y.domain([0, d3.max(data, function (d) { return Math.max(d.nonpromotedprice, d.promotedprice)*1.2; })]).nice();
// Line for the 1st Block
var lines = svg.selectAll("line")
.data(data)
.enter()
.append('line')// attach a line
.style("stroke", "#E6EAEE")
.style("stroke-width", 8) // colour the line
.attr("x1", function (d) { return d.x_value; }) // x position of the first end of the line
.attr("y1", function (d) { return y(d.nonpromotedprice); }) // y position of the first end of the line
.attr("x2", function (d) { return d.x_value; }) // x position of the second end of the line
.attr("y2", function (d) { return y(d.promotedprice); });
// Add the Y Axis
svg.append("g")
.attr("class", "grid")
.attr("fill", "lightgrey")
.attr("stroke-width", 0.7)
.attr("stroke-opacity", 0.2)
.call(d3.axisLeft(y)
.tickSize(-400)
.tickFormat(""));
var topEndPoints = data.map(function (line, i) {
return {
'x': line.x_value,
'y': line.nonpromotedprice,
'marker': 'marker-start',
'lineIndex': i
};
});
var bottomEndPoints = data.map(function (line, i) {
return {
'x': line.x_value,
'y': line.promotedprice,
'marker': 'marker-end',
'lineIndex': i
};
});
var MiddleEndPoints = data.map(function (line, i) {
return {
'x': line.x_value,
'y': line.avgprice,
'marker': 'marker-middle',
'lineIndex': i
};
});
var endPointsData = topEndPoints.concat(bottomEndPoints, MiddleEndPoints);
// Pointer to d3 rectangles
var endPoints = svg
.selectAll('rect')
.data(endPointsData)
.enter()
.append('rect')
.attr("width", 12)
.attr("height", 8)
.attr("x", function (d) { return d.x - 6; })
.attr("y", function (d) { return y(d.y); })
//.attr("cx", function (d) { return d.x; })
//.attr("cy", function (d) { return d.y; })
//.attr('r',7)
.attr("fill", function (d) { return color(d.x); })
.call(d3.drag()
//.origin(function(d) { return y(d.y); })
.subject(function() {
var t = d3.select(this);
return {x: t.attr("x"), y: t.attr("y")};
})
.on("start", dragstarted)
.on("drag", dragged)
.on("end", dragended));
// draw the logo
svg.selectAll("image")
.data(data)
.enter()
.append("svg:image")
.attr("xlink:href", function (d) { return d.logo; })
//.append("rect")
.attr("x", function (d) { return d.x_value - 13; })
.attr("y", function (d) { return y(d.nonpromotedprice + 35); })
.attr("height", 25)
.attr("width", 25);
function dragstarted() {
d3.select(this).classed("active", true).attr('y', d.y = y(d3.event.y));
}
function dragged(d, i) {
var marker = d3.select(this);
// Update the marker properties
marker
//.attr('cx', d.x = d3.event.x)
.attr('y', d.y = d3.event.y);
// Update the line properties
lines
.filter(function (lineData, lineIndex) {
return lineIndex === d.lineIndex;
})
.attr('x1', function (lineData) {
return d.marker === 'marker-start' ? lineData.x1 = d.x : lineData.x1;
})
.attr('y1', function (lineData) {
return d.marker === 'marker-start' ? lineData.y1 = d.y : lineData.y1;
})
.attr('x2', function (lineData) {
return d.marker === 'marker-end' ? lineData.x2 = d.x : lineData.x2;
})
.attr('y2', function (lineData) {
return d.marker === 'marker-end' ? lineData.y2 = d.y : lineData.y2;
});
}
function dragended() {
d3.select(this).classed("active", false);
Shiny.setInputValue("pricechanged",
{price: (d3.max(data, function (d) { return Math.max(d.nonpromotedprice, d.promotedprice); }) -(d3.event.y / 390)* d3.max(data, function (d) { return Math.max(d.nonpromotedprice, d.promotedprice); }))*1.19},
{priority: "event"}
);
}