How to color stroke in path? - d3.js

Question

window.onload = function(){
var margin = {
top: 30,
right: 20,
bottom: 30,
left: 50
};var width = 600 - margin.left - margin.right;
var height = 270 - margin.top - margin.bottom;
var parseDate = d3.timeFormat("%c").parse;
var x = d3.scaleLinear().range([0, width]);
var y = d3.scaleLinear().range([height, 0]);
var xAxis = d3.axisBottom()
.scale(x).ticks(5);
var yAxis = d3.axisLeft()
.scale(y).ticks(5);
var valueline = d3.line()
.x(function (d) {
return x(d.date);
})
.y(function (d) {
return y(d.close);
});
var svg = d3.select("body")
.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 + ")");
// Get the data
var data = [{
date: "1 ",
close: "58.13"
}, {
date: "2 ",
close: "53.98"
}, {
date: "3 ",
close: "67.00"
}, {
date: "4 ",
close: "89.70"
}, {
date: "5 ",
close: "99.00"
}, {
date: "6 ",
close: "20.00"
}];
var data2 = [{
date: "1 ",
close: "52.13"
}, {
date: "2 ",
close: "30.98"
}, {
date: "3 ",
close: "36.00"
}, {
date: "4 ",
close: "40.70"
}, {
date: "5 ",
close: "20.00"
}, {
date: "6 ",
close: "96.00"
}];
data.forEach(function (d) {
d.date = d.date;
d.close = +d.close;
});
// scaleLinear the range of the data
x.domain(d3.extent(data, function (d) {
return d.date;
}));
y.domain([0, d3.max(data, function (d) {
return d.close;
})]);
svg.append("path") // Add the valueline path.
.attr("d", valueline(data)).attr("stroke","red");
svg.append("path") // Add the valueline path.
.attr("d", valueline(data2)).attr("stroke","blue");
svg.append("g") // Add the X Axis
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
svg.append("g") // Add the Y Axis
.attr("class", "y axis")
.call(yAxis);
}
I am new to this. I want to add color to the stroke I am using but I am unable to do it. I have added attribute for applying stroke color in the code but it is not working. I want each of the line to be of different color. Please help me with the feasible solution.

Answer 1

Your code seems to work fine. Here is the d3 way of implementation for the same.
var margin = {
top: 30,
right: 20,
bottom: 30,
left: 50
};
var width = 600 - margin.left - margin.right;
var height = 270 - margin.top - margin.bottom;
var parseDate = d3.timeFormat("%c").parse;
var x = d3.scaleLinear().range([0, width]);
var y = d3.scaleLinear().range([height, 0]);
var xAxis = d3.axisBottom()
.scale(x).ticks(5);
var yAxis = d3.axisLeft()
.scale(y).ticks(5);
var valueline = d3.line()
.x(function(d) {
return x(d.date);
})
.y(function(d) {
return y(d.close);
});
var colors = d3.scaleOrdinal(d3.schemeCategory10);
var svg = d3.select("body")
.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 + ")");
// Get the data
var data = [{
date: "1 ",
close: "58.13"
}, {
date: "2 ",
close: "53.98"
}, {
date: "3 ",
close: "67.00"
}, {
date: "4 ",
close: "89.70"
}, {
date: "5 ",
close: "99.00"
}, {
date: "6 ",
close: "20.00"
}];
var data2 = [{
date: "1 ",
close: "52.13"
}, {
date: "2 ",
close: "30.98"
}, {
date: "3 ",
close: "36.00"
}, {
date: "4 ",
close: "40.70"
}, {
date: "5 ",
close: "20.00"
}, {
date: "6 ",
close: "96.00"
}];
data.forEach(function(d) {
d.date = d.date;
d.close = +d.close;
});
// scaleLinear the range of the data
x.domain(d3.extent(data, function(d) {
return d.date;
}));
y.domain([0, d3.max(data, function(d) {
return d.close;
})]);
svg.selectAll("path.line").data([data, data2])
.enter().
append("path") // Add the valueline path.
.attr("class", "line")
.attr("d", valueline)
.attr("stroke", function(d, i) {
return colors(i);
});
svg.append("g") // Add the X Axis
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
svg.append("g") // Add the Y Axis
.attr("class", "y axis")
.call(yAxis);
path {
fill: none;
}
<script src="https://d3js.org/d3.v4.min.js"></script>d