问题
Below is my line graph where I am using 2 lines to show different values,
One line is blue and the other is red.
I want the line to have sharp points. and i would like the line it sit on the right vaule that i have gievn. for example if '28 dec' is value '4' and '29 dec' is value '2' and '30 dec' is value '5', Right now the values are not exactly hitting the number for example on 'Dec 25' the value is 3 but on the chart the line is going under 3 and it looks like 2.5. is this because the line is a smooth line and not a sharpe one?
I want to see the line go up and down with sharp edges and not smooth. if that makes sense. I hope it makes sense because i am struggling big time on that
the js fiddle i have created is: https://jsfiddle.net/dave1231/cexLbfnk/2/
if someone is able to show me how i would appreciate that a lot.
Thanks you in advance!
This is my HTML:
<div id="LineChart"></div>
This is my CSS:
#search {
position:absolute;
top: -2%;
}
#LineChart{
text-align:center;
}
.tablebad thead tr {
background-color: #eee;
}
.tablegood thead tr th {
background-color: #eee;
}
path.line {
fill: none;
stroke: #004ecc;
stroke-width: 4px;
}
path.line2 {
fill: none;
stroke: #cc0000;
stroke-width: 4px;
}
path.area {
fill: #e7e7e7;
}
.guideline {
margin-right: 100px;
float: right;
}
.axis path,
.axis line {
fill: none;
stroke-width: 5px;
}
.x.axis path {
display: none;
}
.y.axis path {
display: none;
}
.grid .tick {
stroke: black;
stroke-width: 0.2px;
}
#fade p {
text-align: center;
animation: fadein 4s;
-moz-animation: fadein 4s; /* Firefox */
-webkit-animation: fadein 4s; /* Safari and Chrome */
-o-animation: fadein 4s; /* Opera */
}
#fade ul,li {
animation: fadein 4s;
-moz-animation: fadein 4s; /* Firefox */
-webkit-animation: fadein 4s; /* Safari and Chrome */
-o-animation: fadein 4s; /* Opera */
}
@keyframes fadein {
from {
opacity:0;
}
to {
opacity:1;
}
}
@-moz-keyframes fadein { /* Firefox */
from {
opacity:0;
}
to {
opacity:1;
}
}
@-webkit-keyframes fadein { /* Safari and Chrome */
from {
opacity:0;
}
to {
opacity:1;
}
}
@-o-keyframes fadein { /* Opera */
from {
opacity:0;
}
to {
opacity: 1;
}
}
This is my d3.js:
var margin = {
top: 0,
right: 90,
bottom: 30,
left: 50
},
width = 1200 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom,
padding = 1;
var parseDate = d3.time.format("%d-%b-%y").parse;
// Set the ranges
var x = d3.time.scale()
.range([10, width - 15]);
var x2 = d3.scale.ordinal().rangePoints([10, width], .10)
var y = d3.scale.linear()
.range([height, 100]);
var xAxis = d3.svg.axis().scale(x2)
.orient("bottom")
.tickFormat(d3.time.format("%b %d"))
.ticks(4)
.tickPadding(2);
var yAxis = d3.svg.axis().scale(y)
.orient("left");
var valueline = d3.svg.line()
.interpolate("basis")
.x(function(d) {
return x(d.date);
})
.y(function(d) {
return y(d.XMAS);
});
var valueline2 = d3.svg.line()
.interpolate("basis")
.x(function(d) {
return x(d.date);
})
.y(function(d) {
return y(d.JANSALES);
});
//florida
var chart1 = d3.select("#LineChart")
.append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
//needed for the grid
function make_y_axis() {
return d3.svg.axis()
.scale(y)
.orient("left")
}
data1 = [{
"date": "24-Dec-12",
"XMAS": 2,
"JANSALES": 0
}, {
"date": "25-Dec-12",
"XMAS": 3,
"JANSALES": 0
},
{
"date": "26-Dec-12",
"XMAS": 1,
"JANSALES": 0
},
{
"date": "27-Dec-12",
"XMAS": 2.0,
"JANSALES": 0
},
{
"date": "28-Dec-12",
"XMAS": 4.0,
"JANSALES": 0
},
{
"date": "29-Dec-12",
"XMAS": 4.0,
"JANSALES": 0
}
,
{
"date": "29-Dec-12",
"XMAS": 5,
"JANSALES": 0
},
{
"date": "30-Dec-12",
"JANSALES": 3.0
},
{
"date": "31-Dec-12",
"JANSALES": 2.0
},
{
"date": "01-Jan-13",
"JANSALES": 3.0
},
{
"date": "02-Jan-13",
"JANSALES": 1.0
},
{
"date": "03-Jan-13",
"JANSALES": 3.0
},
{
"date": "04-Jan-13",
"JANSALES": 2.0
},
{
"date": "05-Jan-13",
"JANSALES": 2.0
},
{
"date": "06-Jan-13",
"JANSALES": 1.0
},
{
"date": "07-Jan-13",
"JANSALES": 2.0
},
{
"date": "08-Jan-13",
"JANSALES": 2.0
},
{
"date": "09-Jan-13",
"JANSALES": 3.0
},
{
"date": "10-Jan-13",
"JANSALES": 2.0
},
{
"date": "11-Jan-13",
"JANSALES": 3.0
},
{
"date": "12-Jan-13",
"JANSALES": 3.0
},
{
"date": "13-Jan-13",
"JANSALES": 2.0
},
{
"date": "14-Jan-13",
"JANSALES": 1.0
}
];
var color = d3.scale.ordinal().range(["#004ecc", "#cc0000"]);
//d3.csv("data.csv", function(error, data) {
data1.forEach(function(d) {
d.date = parseDate(d.date);
d.XMAS = +d.XMAS;
d.JANSALES = +d.JANSALES;
});
// Scale the range of the data
x.domain(d3.extent(data1, function(d) {
return d.date;
}));
y.domain([0, 10]);
x2.domain(data1.map(function(d) {
return d.date;
}));
//add the grid
chart1.append("g")
.attr("class", "grid")
.call(make_y_axis()
.tickSize(-width, 0, 0)
.tickFormat("")
)
chart1.append("path")
.attr("class", "line")
.attr("stroke", "red")
.attr("d", valueline(data1));
chart1.append("path")
.attr("class", "line2")
.attr("d", valueline2(data1.filter(function(d) {
return d.date > parseDate("29-Dec-12");
})));
// Add the X Axis
chart1.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
// Add the Y Axis
chart1.append("g")
.attr("class", "y axis")
.call(yAxis);
chart1.append("text")
.attr("transform", "translate(" + (width + 3) + "," + y(data1[0].JANSALES) + ")")
.attr("x", ".1em")
.attr("y", "-40")
.attr("text-anchor", "start")
.style("fill", "red")
.style("font-size", "15")
.style("font-weight", "bold")
.text("JAN SALES");
chart1.append("text")
.attr("transform", "translate(" + (width + 3) + "," + y(data1[0].XMAS) + ")")
.attr("x", ".1em")
.attr("y", "10")
.attr("text-anchor", "start")
.style("fill", "steelblue")
.style("font-size", "15")
.style("font-weight", "bold")
.text("XMAS");
//plus 1: animation
var curtain = chart1.append('rect')
.attr('x', -1 * width)
.attr('y', -1 * height - 2)
.attr('height', height)
.attr('width', width)
.attr('class', 'curtain')
.attr('transform', 'rotate(180)')
.style('fill', '#ffffff')
/* Optionally add a guideline */
var guideline = chart1.append('line')
.attr('stroke', '#333')
.attr('stroke-width', 0.4)
.attr('class', 'guide')
.attr('x1', 1)
.attr('y1', 1)
.attr('x2', 1)
.attr('y2', height)
var t = chart1.transition()
.delay(120)
.duration(500)
.ease('linear')
.each('end', function() {
d3.select('line.guide')
.transition()
.style('opacity', 0)
.remove()
});
t.select('rect.curtain')
.attr('width', 0);
t.select('line.guide')
.attr('transform', 'translate(' + width + ', 0)')
d3.select("#show_guideline").on("change", function(e) {
});
回答1:
Just remove the interpolate function here:
var valueline = d3.svg.line()
.interpolate("basis")
.x(function(d) {
return x(d.date);
})
.y(function(d) {
return y(d.XMAS);
});
And do the same in valueline2. Right now you're using basis, which creates a B-spline.
In case you want to set a different interpolation, here is a list of available options in D3 v3.x.
Here is your updated fiddle: https://jsfiddle.net/7apnhbqd/
回答2:
If you don't want d3 to smooth the edges, you should remove the interpolation from the line generator.
https://jsfiddle.net/cexLbfnk/3/
var valueline2 = d3.svg.line()
.interpolate("basis") // this line needs to go
.x(function(d) {
return x(d.date);
})
.y(function(d) {
return y(d.JANSALES);
});
来源：https://stackoverflow.com/questions/43818388/line-chart-not-hitting-the-right-value-on-chart-and-has-a-smooth-line