我正在处理 D3 中的热图图表,但我不知道如何在鼠标悬停时添加文本。我不确定如何进行。如果你能给我一些线索,我将不胜感激。在以下代码段中,您可以找到代码。工作和非工作代码块。谢谢!
console.log(d3)
let screenWidth = 800
let screenHeight = 400
//load data
d3.csv('./datos/locations.csv').then(function(data){
let filtered = []
for(let item of data) {
if(item.location === "location one") {
filtered.push(item)
}
}
build(filtered)
})
//Create canvas
function createSVG() {
let container = d3.select('#container')
svg = container.append('svg')
.attr('id', 'canvas')
.attr('width', screenWidth)
.attr('height', screenHeight)
}
//Create chart
function build(data) {
let rectWidth = screenWidth / 24
let rectHeight = screenHeight / 7
let rects = svg.selectAll('rect')
.data(data)
.enter()
.append('rect')
.attr('x', function(d,i) {
return (parseInt(d.hour) - 1) * rectWidth})
.attr('y', function(d,i){
return (parseInt(d.day) - 1) * rectHeight})
.attr('height', rectHeight)
.attr('width', rectWidth)
.style('fill', 'black')
.style('stroke', 'white')
.on('mouseover', function(d,i) {
let rects = d3.select(this)
.append('text')
.attr('x')
.attr('y')
.style('font-weight', 500)
.style('font-family', 'Arial')
.style('fill', 'red')
.text(function (d,i) {return d.value})})
}
function main() {
createSVG()
build()
}
main()
```