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This is my first time using d3.js, so please bear with me. I am implementing this inside of a vue.js file as pure javascript.
I am trying to make a scatter plot with zooming capabilities. So far I have everything nearly working, but when I zoom I notice that the x-axis isn't scaling properly, but the y-axis is working properly. For instance, when looking at the original plot, a point may be at around 625 on the x-axis, but after zooming in the same point will be less than 600. This is not happening with the y-axis - those points scale properly. I am assuming that something is wrong with the scaling of the x-axis in my zoom function, but I just can't figure it out. Please take a look, and let me know if you can see where I went wrong.
Edit: I should mention that this is using d3.js version 7.4.4
<template>
<div id="reg_plot"></div>
</template>
<script>
import * as d3 from 'd3';
export default {
name: 'regCamGraph',
components: {
d3
},
methods: {
createSvg() {
// dimensions
var margin = {top: 20, right: 20, bottom: 30, left: 40},
svg_dx = 1400,
svg_dy =1000,
chart_dx = svg_dx - margin.right - margin.left,
chart_dy = svg_dy - margin.top - margin.bottom;
// data
var y = d3.randomNormal(400, 100);
var x_jitter = d3.randomUniform(-100, 1400);
var d = d3.range(1000)
.map(function() {
return [x_jitter(), y()];
});
// fill
var colorScale = d3.scaleLinear()
.domain(d3.extent(d, function(d) { return d[1]; }))
.range([0, 1]);
// y position
var yScale = d3.scaleLinear()
.domain(d3.extent(d, function(d) { return d[1]; }))
.range([chart_dy, margin.top]);
// x position
var xScale = d3.scaleLinear()
.domain(d3.extent(d, function(d) { return d[0]; }))
.range([margin.right, chart_dx]);
console.log("chart_dy: " + chart_dy);
console.log("margin.top: " + margin.top);
console.log("chart_dx: " + chart_dx);
console.log("margin.right: " + margin.right);
// y-axis
var yAxis = d3.axisLeft(yScale);
// x-axis
var xAxis = d3.axisBottom(xScale);
// zoom
var svg = d3.select("#reg_plot")
.append("svg")
.attr("width", svg_dx)
.attr("height", svg_dy);
svg.call(d3.zoom().on("zoom", zoom)); // ref [1]
// plot data
var circles = svg.append("g")
.attr("id", "circles")
.attr("transform", "translate(200, 0)")
.selectAll("circle")
.data(d)
.enter()
.append("circle")
.attr("r", 4)
.attr("cx", function(d) { return xScale(d[0]); })
.attr("cy", function(d) { return yScale(d[1]); })
.style("fill", function(d) {
var norm_color = colorScale(d[1]);
return d3.interpolateInferno(norm_color)
});
// add y-axis
var y_axis = svg.append("g")
.attr("id", "y_axis")
.attr("transform", "translate(75,0)")
.call(yAxis).style("font-size", "20px")
// add x-axis
var x_axis = svg.append("g")
.attr("id", "x_axis")
.attr("transform", `translate(${margin.left}, ${svg_dy - margin.bottom})`)
.call(xAxis).style("font-size", "20px")
function zoom(e) {
// re-scale y axis during zoom
y_axis.transition()
.duration(50)
.call(yAxis.scale(e.transform.rescaleY(yScale)));
// re-scale x axis during zoom
x_axis.transition()
.duration(50)
.call(xAxis.scale(e.transform.rescaleX(xScale)));
// re-draw circles using new y-axis scale
var new_xScale = e.transform.rescaleX(xScale);
var new_yScale = e.transform.rescaleY(yScale);
console.log(d);
x_axis.call(xAxis.scale(new_xScale));
y_axis.call(yAxis.scale(new_yScale));
circles.data(d)
.attr('cx', function(d) {return new_xScale(d[0])})
.attr('cy', function(d) {return new_yScale(d[1])});
}
}
},
mounted() {
this.createSvg();
}
}
</script>
Interestingly enough, after I set the clip region to prevent showing points outside of the axes the problem seemed to resolve itself. This is how I created the clip path:
// clip path
var clip = svg.append("defs").append("svg:clipPath")
.attr("id", "clip")
.append("svg:rect")
.attr("id", "clip-rect")
.attr("x", "0")
.attr("y", "0")
.attr('width', chart_dx)
.attr('height', chart_dy);
And I then added that attribute to the svg when plotting the data like this:
svg.append("g").attr("clip-path", "url(#clip)")
Updated clip path with plot data section:
// clip path
var clip = svg.append("defs").append("svg:clipPath")
.attr("id", "clip")
.append("svg:rect")
.attr("id", "clip-rect")
.attr("x", "0")
.attr("y", "0")
.attr('width', chart_dx)
.attr('height', chart_dy);
// plot data
var circles = svg.append("g")
.attr("id", "circles")
.attr("transform", "translate(75, 0)")
.attr("clip-path", "url(#clip)") //added here
.selectAll("circle")
.data(d)
.enter()
.append("circle")
.attr("r", 4)
.attr("cx", function(d) { return xScale(d[0]); })
.attr("cy", function(d) { return yScale(d[1]); })
.style("fill", function(d) {
var norm_color = colorScale(d[1]);
return d3.interpolateInferno(norm_color)
});
I ended up resolving this issue. I have updated the original post to show what worked for me.
Basically, after adding the clip region things started to work properly.
// clip path (this is the new clip region that I added. It prevents dots from being drawn outside of the axes.
var clip = svg.append("defs").append("svg:clipPath")
.attr("id", "clip")
.append("svg:rect")
.attr("id", "clip-rect")
.attr("x", "0")
.attr("y", "0")
.attr('width', chart_dx)
.attr('height', chart_dy);
// plot data
var circles = svg.append("g")
.attr("id", "circles")
.attr("transform", "translate(75, 0)")
.attr("clip-path", "url(#clip)") //added clip region to svg here
.selectAll("circle")
.data(d)
.enter()
.append("circle")
.attr("r", 4)
.attr("cx", function(d) { return xScale(d[0]); })
.attr("cy", function(d) { return yScale(d[1]); })
.style("fill", function(d) {
var norm_color = colorScale(d[1]);
return d3.interpolateInferno(norm_color)
});
Currently, in case of D3 Hierarchical Bar Chart, Each blue bar represents a folder, whose length encodes the total size of all files in that folder (and all subfolders). I want that the blue bar should encode the length (not size) of the total no. of items within it. For example, in below example if I click on 'vis', it has 7 items within it. Therefore, the the length of the bar for 'vis' should be 7. Similarly for all items in all folders. Here's the link - https://bl.ocks.org/mbostock/1283663
<!DOCTYPE html>
<html>
<head>
<style>
text {
font: 10px sans-serif;
}
rect.background {
fill: white;
}
.axis {
shape-rendering: crispEdges;
}
.axis path,
.axis line {
fill: none;
stroke: #000;
}
</style>
<title>D3</title>
</head>
<body>
<script src="http://d3js.org/d3.v3.js"></script>
<script>
var margin = {top: 30, right: 30, bottom: 40, left: 50},
width = window.innerWidth - margin.left - margin.right-100,
height = window.innerHeight - margin.top - margin.bottom-100;
var y = d3.scale.linear()
.range([height, 0]);
var barHeight = 20;
var color = d3.scale.ordinal()
.range(["steelblue", "#ccc"]);
var duration = 750,
delay = 25;
var partition = d3.layout.partition()
.value(function(d) { return d.size; });
var yAxis = d3.svg.axis()
.scale(y)
.orient("left");
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 + ")");
svg.append("rect")
.attr("class", "background")
.attr("width", width)
.attr("height", height)
.on("click", up);
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0, " + height + ")")
.append("line")
.attr("x1", "100%");
svg.append("g")
.attr("class", "y axis");
d3.json("https://jsonblob.com/api/f577d19c-0f2b-11e7-a0ba-09040711ce47", function(error, root) {
if (error) throw error;
partition.nodes(root);
y.domain([0, root.value]).nice();
down(root, 1000);
});
function down(d,i) {
if (!d.children || this.__transition__) return;
var end = duration + d.children.length * delay;
// Mark any currently-displayed bars as exiting.
var exit = svg.selectAll(".enter")
.attr("class", "exit");
// Entering nodes immediately obscure the clicked-on bar, so hide it.
exit.selectAll("rect").filter(function(p) { return p === d; })
.style("fill-opacity", 1e-6);
// Enter the new bars for the clicked-on data.
// Per above, entering bars are immediately visible.
var enter = bar(d)
.attr("transform", stack(i))
.style("opacity", 1);
// Have the text fade-in, even though the bars are visible.
// Color the bars as parents; they will fade to children if appropriate.
enter.select("text").style("fill-opacity", 1e-6);
enter.select("rect").style("fill", color(true));
// Update the x-scale domain.
y.domain([0, d3.max(d.children, function(d) { return d.value; })]).nice();
// Update the x-axis.
svg.selectAll(".y.axis").transition()
.duration(duration)
.call(yAxis);
// Transition entering bars to their new position.
var enterTransition = enter.transition()
.duration(duration)
.delay(function(d, i) { return i * delay; })
.attr("transform", function(d, i) { return "translate(" + barHeight * i * 2.5 + "," + 0 + ")"; });
// Transition entering text.
enterTransition.select("text")
.style("fill-opacity", 1);
// Transition entering rects to the new y-scale.
enterTransition.select("rect")
.attr("y", function(d) { return y(d.value); })
.attr("height", function(d) { return height - y(d.value); })
.style("fill", function(d) { return color(!!d.children); });
// Transition exiting bars to fade out.
var exitTransition = exit.transition()
.duration(duration)
.style("opacity", 1e-6)
.remove();
// Transition exiting bars to the new y-scale.
exitTransition.selectAll("rect")
.attr("height", function(d) { return height - y(d.value); });
// Rebind the current node to the background.
svg.select(".background")
.datum(d)
.transition()
.duration(end);
d.index = i;
}
function up(d) {
if (!d.parent || this.__transition__) return;
var end = duration + d.children.length * delay;
// Mark any currently-displayed bars as exiting.
var exit = svg.selectAll(".enter")
.attr("class", "exit");
// Enter the new bars for the clicked-on data's parent.
var enter = bar(d.parent)
.attr("transform", function(d, i) { return "translate(" + barHeight * i * 2.5 + "," + 0 + ")"; })
.style("opacity", 1e-6);
// Color the bars as appropriate.
// Exiting nodes will obscure the parent bar, so hide it.
enter.select("rect")
.style("fill", function(d) { return color(!!d.children); })
.filter(function(p) { return p === d; })
.style("fill-opacity", 1e-6);
// Update the y-scale domain.
y.domain([0, d3.max(d.parent.children, function(d) { return d.value; })]).nice();
// Update the y-axis.
svg.selectAll(".y.axis").transition()
.duration(duration)
.call(yAxis);
// Transition entering bars to fade in over the full duration.
var enterTransition = enter.transition()
.duration(end)
.style("opacity", 1);
// Transition entering rects to the new y-scale.
// When the entering parent rect is done, make it visible!
enterTransition.select("rect")
.attr("height", function(d) { return height - y(d.value); })
.attr("y", function(d) { return y(d.value); })
.each("end", function(p) { if (p === d) d3.select(this).style("fill-opacity", null); });
// Transition exiting bars to the parent's position.
var exitTransition = exit.selectAll("g").transition()
.duration(duration)
.delay(function(d, i) { return i * delay; })
.attr("transform", stack(d.index));
// Transition exiting text to fade out.
exitTransition.select("text")
.style("fill-opacity", 1e-6);
// Transition exiting rects to the new scale and fade to parent color.
exitTransition.select("rect")
.attr("height", function(d) { return height - y(d.value); })
.attr("y", function(d) { return y(d.value); })
.style("fill", color(true));
// Remove exiting nodes when the last child has finished transitioning.
exit.transition()
.duration(end)
.remove();
// Rebind the current parent to the background.
svg.select(".background")
.datum(d.parent)
.transition()
.duration(end);
}
// Creates a set of bars for the given data node, at the specified index.
function bar(d) {
var bar = svg.insert("g", ".x.axis")
.attr("class", "enter")
.attr("transform", "translate(15,0)")
.selectAll("g")
.data(d.children)
.enter().append("g")
.style("cursor", function(d) { return !d.children ? null :
"pointer"; })
.on("click", down);
bar.append("text")
.attr("x", barHeight / 2)
.attr("y", height + 10)
.attr("dy", ".35em")
.style("text-anchor", "start")
.text(function(d) { return d.name; })
.attr("transform", "rotate(45 " + (barHeight / 2) + " " + (height +
10) + ")")
bar.append("rect")
.attr("width", barHeight)
.attr("height", function(d) { return height - y(d.value); })
.attr("y", function(d) { return y(d.value); });
return bar;
}
// A stateful closure for stacking bars horizontally.
function stack(i) {
var y0 = 0;
return function(d) {
var tx = "translate(" + barHeight * i * 1.5 + "," + y0 + ")";
y0 += y(d.value);
return tx;
};
}
bar.append("rect")
.attr("width", barHeight)
.attr("height", function(d) { return height - y(d.value); })
the d.value defines the number that is used to display.
if you need something else, pick the property of the object (d) that is relevant to you.
I have created group bar chart by using D3.js. Each group has 2 bars. When any bar is clicked it must show some data using custom alert box. Now the bar can click and it shows data.
var state = svg.selectAll(".TestSuite")
.data(data)
.enter().append("g")
.attr("class", "TestSuite")
.on("click", function(d,i) {
if(i==0){
Alert.render(d3.select(this).data()[0].FalseStatements);
}else{
Alert.render(d3.select(this).data()[0].TrueStatements);
}
})
.attr("transform", function (d) {
return "translate(" + x0(d.TestSuite) + ",0)";
});
But data is vary according to clicked bars. So how to identify each single bar within a single group uniquely.
Here "if condition" that I used does not do the thing I want.How do I correct it?
Thank you.
(Suppose one group of bar consists two bars, one shows true count and other shows false count for a particular scenario. When we click the bar which shows true count then it should appear "TrueStatements" which is already have in data.using d3.select(this).data()[0].TrueStatements can do this. And also when someone click the bar which shows false count then it should appear "FalseStatements" which is already have in data.using d3.select(this).data()[0].FalseStatements can do this. My question is how do we identify the bar which shows true count and the bar which shows false count uniquely for do this task.)
EDITED:
How I get the data for bar chart(This is inside a for loop)
originalDataSetForBarChart.push({
TestSuite: "TS"+treeIndex,
Pass: trueAppear,
Fail: falseAppear,
FalseStatements : falseStatement,
TrueStatements : trueStatement
});
Bar chart code
var margin = {
top: 20,
right: 10,
bottom: 30,
left: 40
},
width = 890 - margin.left - margin.right,
height = 300 - margin.top - margin.bottom;
var x0 = d3.scale.ordinal()
.rangeRoundBands([0, width], .5);
var x1 = d3.scale.ordinal();
var y = d3.scale.linear()
.range([height, 0]);
var color = d3.scale.ordinal()
.range(["#4169E1", "#800080"]);
var xAxis = d3.svg.axis()
.scale(x0)
.orient("bottom");
var yAxis = d3.svg.axis()
.scale(y)
.orient("left")
.tickFormat(d3.format(""));
var w = width + margin.left + margin.right;
var h = height + margin.top + margin.bottom;
var svg = d3.select(".chart1").append("svg")
.attr("width", w)
.attr("height", h)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
//svg.call(tip);
var xg = svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")");
var yg = svg.append("g")
.attr("class", "y axis");
yg.append("text")
.attr("transform", "rotate(-90)")
.attr("y", 6)
.attr("dy", ".71em")
.style("text-anchor", "end")
.text("Count");
I append bars to this chart inside a setInterval function using following method.
function update() {
startTime_barChart = new Date().getTime();
for (var i = 0; i < data.length; i++) {
var testSuite = d3.keys(data[i]).filter(function (key) {
return key !== "TestSuite";
});
}
data.forEach(function (d) {
d.trueFalseCount = testSuite.map(function (name) {
return {
name: name,
value: +d[name]
};
});
});
x0.domain(data.map(function (d) {
return d.TestSuite;
}));
x1.domain(testSuite).rangeRoundBands([0, x0.rangeBand()]);
y.domain([0, d3.max(data, function (d) {
return d3.max(d.trueFalseCount, function (d) {
return d.value;
});
})]);
//making the x axis/y axis
xg.call(xAxis);
yg.call(yAxis);
//removing all the rectangles
svg.selectAll(".TestSuite").remove();
var tip_word;
var tip = d3.tip()
.attr('class', 'd3-tip')
.offset([-10, 0])
.html(function(d) {
tip_word= "<strong style='color:white'>"+
"Pass count :"+
"</strong>"+
" <span style='color:white'>" + d.True +
"</span></br>"+
"<strong style='color:white'>"+
"Fail count :"+
"</strong>"+
" <span style='color:white'>" + d.False +
"</span>";
return word;
});
var state = svg.selectAll(".TestSuite")
.data(data)
.enter().append("g")
.attr("class", "TestSuite")
.on("click", function(d,i) {
if(i%2 == 0){//How to set this condition
Alert.render(d3.select(this).data()[0].FalseStatements);
}else{
Alert.render(d3.select(this).data()[0].TrueStatements);
}
})
.attr("transform", function (d) {
return "translate(" + x0(d.TestSuite) + ",0)";
});
svg.call(tip);
state.selectAll("rect")
.data(function (d) {
return d.trueFalseCount;})
.enter().append("rect")
.attr("width", x1.rangeBand())
.attr("x", function (d) {
return x1(d.name);
})
.attr("y", function (d) {
return y(d.value);
})
.attr("height", function (d) {
return height - y(d.value);
})
.style("fill", function (d) {
return color(d.name);
});
if(barChartLegentController==1){
var legend = svg.selectAll(".legend")
.data(testSuite.slice().reverse())
.enter().append("g")
.attr("class", "legend")
.attr("transform", function(d, i) { return "translate(0," + i * 20 + ")"; });
legend.append("rect")
.attr("x", width - 18)
.attr("width", 18)
.attr("height", 18)
.style("fill", color);
legend.append("text")
.attr("x", width - 24)
.attr("y", 9)
.attr("dy", ".35em")
.style("text-anchor", "end")
.text(function(d) { return d; });
barChartLegentController=2;
}
endTime_barChart = new Date().getTime();
var totalbar = (endTime_barChart-startTime_barChart)/1000;
//alert('Total bar time : '+ totalbar+' seconds');
}
I'm not sure I fully understand what you are asking yet but the best way to identifying any element/entity is with an id, something like the following:
d3.select(this).attr(id, function(d, i) {return 'bar_' + i});
Add this inside the iterative function where you are creating your bars. In this way you will be able to select them from anywhere in your code with a d3.select('#bar_1).
If you only want to identify each bar it would be something like this:
var state = svg.selectAll(".TestSuite")
.data(data)
.enter().append("g")
.attr("id", function(d,i) {return 'bar_' + i})
.attr("class", "TestSuite")
.on("click", function(d,i) {
if(i==0){
Alert.render(d3.select(this).data()[0].FalseStatements);
}else{
Alert.render(d3.select(this).data()[0].TrueStatements);
}
})
.attr("transform", function (d) {
return "translate(" + x0(d.TestSuite) + ",0)";
});
In the case that you would like to identify each bar with an Id related to its contents (true or false statements) I would suggest something like the following:
var state = svg.selectAll(".TestSuite")
.data(data)
.enter().append("g")
.attr("class", "TestSuite")
.on("click", function(d,i) {
var barId;
if(i==0){
barId = 'falseBar_' + i;
Alert.render(d3.select(this).data()[0].FalseStatements);
}else{
barId = 'trueBar_' + i;
Alert.render(d3.select(this).data()[0].TrueStatements);
}
d3.select(this).attr('id', barId);
})
.attr("transform", function (d) {
return "translate(" + x0(d.TestSuite) + ",0)";
});
In any case, this will assign an unique Id to every bar (i.e. "bar_25" or "falseBar_14") to each bar, giving you an ideal way to identify each bar.
EDIT: After OP showed me the actual code they are working with, the following are my suggestions for a solution (which are actually on the same lines as the code above).
The code you should actually be tinkering with is the one below the code you posted. It is where the actual bars are rendered:
state.selectAll("rect")
.data(function(d) { return d.ages; })
.enter().append("rect")
.attr("width", x1.rangeBand())
.attr("x", function(d) { return x1(d.name); })
.attr("y", function(d) { return y(d.value); })
.attr("height", function(d) { return height - y(d.value); })
.style("fill", function(d) { return color(d.name); });
My suggestion to add an id attribute to each bar would be the following:
state.selectAll("rect")
.data(function(d) { return d.ages; })
.enter().append("rect")
.attr("width", x1.rangeBand())
.attr("id", function(d, i) {return 'bar_' + i}) // <-- Edited line
.attr("x", function(d) { return x1(d.name); })
.attr("y", function(d) { return y(d.value); })
.attr("height", function(d) { return height - y(d.value); })
.style("fill", function(d) { return color(d.name); });
It is important that you understand why this, and not the code block you provided initially, is the pertinent one. As you well said, the first block renders each group of bars (hence the append("g") which stands for svg group). The second block starts with a append("rect") which means svg rectangle. This and other lines (i.e. style("fill")..., attr("x")... and attr("y")...) clearly give away that this block is the one dealing with the actual bars and not the groups.
I'm developing a stacked chart application.
http://jsfiddle.net/NYEaX/174/
I've placed it inside a jquery plugin to create multiple instances etc... different properties and eventually different data sources.
For now I am having problems animating the chart bars and the axis.
Animate bar code
animateBars: function(selector, data){
var w = $(selector).data("width");
var h = $(selector).data("height");
var margin = methods.getMargin(h);
methods.setDimensions(w, h, margin);
//methods.setX();
//methods.setY();
//methods.setDomain(data);
var initialHeight = 0;
//var svg = d3.select(selector + " .stackedchart");
var barholder = d3.select(selector + " .barholder");
var state = barholder.selectAll(".state")
.data(data)
.enter()
.append("g")
.attr("class", "g")
.attr("x", function(d) {
return methods.x(d.Label);
})
.attr("transform", function(d) {
return "translate(" + methods.x(d.Label) + ",0)";
});
var bar = state.selectAll("rect")
.data(function(d) {
return d.blocks;
});
// Enter
bar.enter()
.append("rect")
.attr("width", methods.x.rangeBand())
.attr("y", function(d) {
return methods.y(d.y1);
})
.attr("height", function(d) {
return methods.y(d.y0) - methods.y(d.y1);
})
.style("fill", function(d) {
return methods.color(d.name);
});
// Update
bar
.attr("y", function(d) {
return methods.y(d.y1);
})
.attr("height", function(d) {
return methods.y(d.y0) - methods.y(d.y1);
})
.transition()
.duration(500)
.attr("x", function(d) {
return methods.x(d.Label);
})
.attr("width", methods.x.rangeBand())
.attr("y", function(d) {
return methods.y(d.y1);
})
.attr("height", function(d) {
return methods.y(d.y0) - methods.y(d.y1);
});
// Exit
bar.exit()
.transition()
.duration(250)
.attr("y", function(d) {
return methods.y(d.y1);
})
.attr("height", function(d) {
return methods.y(d.y0) - methods.y(d.y1);
})
.remove();
}
One problem is that "state" is generated from the "enter()" method, so all your "bar" calls are only being executed when your "g.class" is being generated, not on update. Change this:
var state = barholder.selectAll(".state")
.data(data)
.enter()
.append("g")...
to this:
var state = barholder.selectAll(".state")
.data(data);
state.enter().append("g")...
See if that helps a bit. It doesn't seem to affect your fiddle, but you might be having problems other than d3. Try simplifying your fiddle and get the d3 stuff working by itself first.
I am having issues trying to build this jquery based d3.js barchart plugin.
the bars are displaced to the left, not sure why
the bars are not updating to new data.
I've tried to get the bars to animate - but not had any success.
http://jsfiddle.net/NYEaX/161/
Here is the animate bars function
animateBars: function(data){
var svg = d3.select(methods.el["selector"] + " .barchart");
var bars = svg.selectAll(".bar")
.data(data);
bars
.enter().append("rect")
.attr("class", "bar")
.attr("x", function(d) { return methods.x(d.letter); })
.attr("width", methods.x.rangeBand())
.attr("y", function(d) { return methods.y(d.frequency); })
.attr("height", function(d) { return methods.height - methods.y(d.frequency); })
.transition()
.duration(300)
bars
.transition()
.duration(300)
bars.exit()
.transition()
.duration(300)
}
I fixed the transition for new bars in your jsfiddle. I hope it reveals the functionality of transitions:
http://jsfiddle.net/NYEaX/893/
How it works: After it sets the initial height and y value, it adds a transition to the end height and y value.
bars
.enter().append("rect")
.attr("class", "bar")
.attr("x", function(d) { return methods.x(d.letter); })
.attr("width", methods.x.rangeBand())
.attr("y", function(d) { return methods.y(0); })
.attr("height", function(d) { return methods.height - methods.y(0); })
.transition().duration(1000)
.attr("y", function(d) { return methods.y(d.frequency); })
.attr("height", function(d) { return methods.height - methods.y(d.frequency); });