How to rotate and change font size on x axis - d3.js

Question

I am new to D3 and I am trying to create some charts based on weather (temperature) data. I have created a separate js file with my code so that all the charts are called from one HTML page. However, the x-axis is very cluttered because I have daily data displayed.
Here is the main js file - how do I make the x-axis rotate and insert space between the days to display? Or alternatively, just show each month (April, May, June, etc.) rather than each day?
(function (){
var VIZ = {};
var margin = {top: 20, right: 55, bottom: 50, left: 20},
width = 1000 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
var parseDate = d3.time.format("%d/%m/%Y").parse;
var x = d3.scale.ordinal()
.rangeRoundBands([0, width], .1);
var y = d3.scale.linear()
.rangeRound([height, 0]);
var xAxis = d3.svg.axis()
.scale(x)
.orient("bottom");
var yAxis = d3.svg.axis()
.scale(y)
.orient("left");
var color = d3.scale.ordinal()
.range(['blue', 'red', 'green','yellow']);
var svg = d3.select("#chart").append("svg")
.attr("id", "thesvg")
.attr("viewBox", "0 0 1000 500")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
function make_x_axis() {
return d3.svg.axis()
.scale(x)
.orient("bottom")
.ticks(20)
}
function make_y_axis() {
return d3.svg.axis()
.scale(y)
.orient("left")
.ticks(20)
}
VIZ.stackChart = function (data, offset) {
var stack = d3.layout.stack()
.values(function (d) { return d.values; })
.x(function (d) { return x(d.label) + x.rangeBand() / 2; })
.y(function (d) { return d.value; });
var area = d3.svg.area()
.interpolate("cardinal")
.x(function (d) { return x(d.label) + x.rangeBand() / 2; })
.y0(function (d) { return y(d.y0); })
.y1(function (d) { return y(d.y0 + d.y); });
var labelVar = 'date';
var varNames = d3.keys(data[0])
.filter(function (key) { return key !== labelVar;});
color.domain(varNames);
var seriesArr = [], series = {};
varNames.forEach(function (name) {
series[name] = {name: name, values:[]};
seriesArr.push(series[name]);
});
data.forEach(function (d) {
varNames.map(function (name) {
series[name].values.push({name: name, label: d[labelVar], value: +d[name]});
});
});
x.domain(data.map(function (d) { return d.date; }));
stack.offset(offset)
stack(seriesArr);
y.domain([0, d3.max(seriesArr, function (c) {
return d3.max(c.values, function (d) { return d.y0 + d.y; });
})]);
var selection = svg.selectAll(".series")
.data(seriesArr)
.enter().append("g")
.attr("class", "series");
selection.append("path")
.attr("class", "streamPath")
.attr("d", function (d) { return area(d.values); })
.style("fill", function (d) { return color(d.name); })
.style("stroke", "grey");
var points = svg.selectAll(".seriesPoints")
.data(seriesArr)
.enter().append("g")
.attr("class", "seriesPoints");
points.selectAll(".point")
.data(function (d) { return d.values; })
.enter().append("circle")
.attr("class", "point")
.attr("cx", function (d) { return x(d.label) + x.rangeBand() / 2; })
.attr("cy", function (d) { return y(d.y0 + d.y); })
.attr("r", "10px")
.style("fill",function (d) { return color(d.name); })
.on("mouseover", function (d) { showPopover.call(this, d); })
.on("mouseout", function (d) { removePopovers(); })
drawAxis();
drawLegend(varNames);
}
VIZ.lineChart = function (data) {
var line = d3.svg.line()
.interpolate("linear")
.x(function (d) { return x(d.label) + x.rangeBand() / 2; })
.y(function (d) { return y(d.value); });
var labelVar = 'date';
var varNames = d3.keys(data[0]).filter(function (key) { return key !== labelVar;});
color.domain(varNames);
var seriesData = varNames.map(function (name) {
return {
name: name,
values: data.map(function (d) {
return {name: name, label: d[labelVar], value: +d[name]};
})
};
});
x.domain(data.map(function (d) { return d.date; }));
y.domain([
d3.min(seriesData, function (c) {
return d3.min(c.values, function (d) { return d.value; });
}),
d3.max(seriesData, function (c) {
return d3.max(c.values, function (d) { return d.value; });
})
]);
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis)
svg.append("g")
.attr("class", "y axis")
.call(yAxis)
var series = svg.selectAll(".series")
.data(seriesData)
.enter().append("g")
.attr("class", "series");
series.append("path")
.attr("class", "line")
.attr("d", function (d) { return line(d.values); })
.style("stroke", function (d) { return color(d.name); })
.style("stroke-width", "4px")
.style("fill", "none")
series.selectAll(".linePoint")
.data(function (d) { return d.values; })
.enter().append("circle")
.attr("class", "linePoint")
.attr("cx", function (d) { return x(d.label) + x.rangeBand()/2; })
.attr("cy", function (d) { return y(d.value); })
.attr("r", "5px")
.style("fill", function (d) { return color(d.name); })
.style("stroke", "grey")
.style("stroke-width", "1px")
.on("mouseover", function (d) { showPopover.call(this, d); })
.on("mouseout", function (d) { removePopovers(); })
svg.append("g")
.attr("class", "grid")
.attr("transform", "translate(0," + height + ")")
.call(make_x_axis()
.tickSize(-height, 0, 0)
.tickFormat("")
)
svg.append("g")
.attr("class", "grid")
.call(make_y_axis()
.tickSize(-width, 0, 0)
.tickFormat("")
)
drawAxis();
drawLegend(varNames);
}
VIZ.stackBarChart = function (data) {
var labelVar = 'date';
var varNames = d3.keys(data[0]).filter(function (key) { return key !== labelVar;});
color.domain(varNames);
data.forEach(function (d) {
var y0 = 0;
d.mapping = varNames.map(function (name) {
return {
name: name,
label: d[labelVar],
y0: y0,
y1: y0 += +d[name]
};
});
d.total = d.mapping[d.mapping.length - 1].y1;
});
x.domain(data.map(function (d) { return d.date; }));
y.domain([0, d3.max(data, function (d) { return d.total; })]);
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis)
.selectAll("text")
.style("text-anchor", "end")
.attr("dx", "-.8em")
.attr("dy", ".15em")
.attr("transform", function(d) {
return "rotate(-65)"
});
svg.append("g")
.attr("class", "y axis")
.call(yAxis)
.append("text")
.attr("transform", "rotate(-90)")
.attr("y", 6)
.attr("dy", ".71em")
.style("text-anchor", "end")
.text("");
var selection = svg.selectAll(".series")
.data(data)
.enter().append("g")
.attr("class", "series")
.attr("transform", function (d) { return "translate(" + x(d.date) + ",0)"; });
selection.selectAll("rect")
.data(function (d) { return d.mapping; })
.enter().append("rect")
.attr("width", x.rangeBand())
.attr("y", function (d) { return y(d.y1); })
.attr("height", function (d) { return y(d.y0) - y(d.y1); })
.style("fill", function (d) { return color(d.name); })
.style("stroke", "grey")
.on("mouseover", function (d) { showPopover.call(this, d); })
.on("mouseout", function (d) { removePopovers(); })
drawAxis();
drawLegend(varNames);
}
VIZ.clearAll = function () {
svg.selectAll("*").remove()
}
function drawAxis() {
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
svg.append("g")
.attr("class", "y axis")
.call(yAxis)
.append("text")
.attr("transform", "rotate(-90)")
.attr("y", 6)
.attr("dy", ".71em")
.style("text-anchor", "end")
.text("Maximum Temperature");
}
function drawLegend (varNames) {
var legend = svg.selectAll(".legend")
.data(varNames.slice().reverse())
.enter().append("g")
.attr("class", "legend")
.attr("transform", function (d, i) { return "translate(55," + i * 20 + ")"; });
legend.append("rect")
.attr("x", width - 10)
.attr("width", 10)
.attr("height", 10)
.style("fill", color)
.style("stroke", "grey");
legend.append("text")
.attr("x", width - 12)
.attr("y", 6)
.attr("dy", ".35em")
.style("text-anchor", "end")
.text(function (d) { return d; });
}
function removePopovers () {
$('.popover').each(function() {
$(this).remove();
});
}
function showPopover (d) {
$(this).popover({
title: d.name,
placement: 'auto top',
container: 'body',
trigger: 'manual',
html : true,
content: function() {
return "Date: " + d.label +
"<br/>Temperature: " + d3.format(",")(d.value ? d.value: d.y1 - d.y0); }
});
$(this).popover('show')
}
VIZ.onResize = function () {
var aspect = 1000 / 500, chart = $("#thesvg");
var targetWidth = chart.parent().width();
chart.attr("width", targetWidth);
chart.attr("height", targetWidth / aspect);
}
window.VIZ = VIZ;
}())

Answer 1

You can rotate texts in x axis using transform attribute.
svg.select(".x.axis")
.selectAll("text")
.attr("transform"," translate(0,15) rotate(-65)"); // To rotate the texts on x axis. Translate y position a little bit to prevent overlapping on axis line.
.style("font-size","15px"); //To change the font size of texts
Use tickformat function of d3 scale for date formatting. To display only month from date, you can use the code below.
var xAxis = d3.svg.axis()
.scale(x)
.orient('bottom')
.tickFormat(d3.time.format('%B'));
Update:
I think, it would be better if you reduce the number of ticks using ticks method to make texts readable.
xAxis.ticks(d3.time.day, 20);
You can refer more about d3 svg axis from here and about time formats from here

Answer 2

I guess things must have changed since the original answer was posted in 2014. In any case, in D3.js versions 5 and up, the mentioned selection code no longer works.
Since the structure of the tick is now a group, for example:
<g class="tick" opacity="1" transform="translate(0.5,0)">
<line stroke="currentColor" y2="6"></line>
<text fill="currentColor" y="9" dy="0.71em">0.0</text>
</g>
...
The selection code needs to be modified like this:
svg.select(".x.axis")
.selectAll(".tick text")
...