问题
Say we have the following crossfilter / dc.js app:
While this is nice, the user loses "reference" the population when brushing. I would like for charts x, y, z, and a to keep the "underlying" bars when other charts are brushed. Perhaps in a different color like so:
I believe this may require updating the dc.renderAll() function, but I am not sure even how to start.
Here is all the code to reproduce this app with the .csv data hosted as a gist.
<!DOCTYPE html>
<html lang="en">
<head>
<title>Data Exploration Tool MVP</title>
<meta charset="UTF-8">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css"/>
<link rel="stylesheet" href="http://unpkg.com/dc@3/dc.css"/>
<style>
#data-count {
margin-top: 0;
text-align: left;
float: none;
}
table {
table-layout: fixed;
}
td {
width: 1%;
}
</style>
</head>
<body>
<div class="container-fluid" style="margin: 10px;">
<div class="row">
<h2>Data Exploration Tool</h2>
<div class="col-md-3 well well-sm">
<div class="dc-data-count" id="data-count">
<span class="filter-count"></span>
selected out of
<span class="total-count"></span>
points |
<a href="javascript:dc.filterAll(); dc.renderAll();">Reset All</a><br>
</div>
</div>
</div>
<div class="row">
<div class="col-md-12">
<!-- First row of charts -->
<div class="row">
<div class="col-md-3">
<div id="chart-11" style="width:100%;">
<div id="chart-11-title"></div>
<div class="reset" style="visibility: hidden;">range: <span class="filter"></span>
<a href="javascript:chart_11.filterAll();dc.redrawAll();">reset</a>
</div>
</div>
</div>
<div class="col-md-3">
<div id="chart-12" style="width:100%;">
<div id="chart-12-title"></div>
<div class="reset" style="visibility: hidden;">selected: <span class="filter"></span>
<a href="javascript:chart_12.filterAll();dc.redrawAll();">reset</a>
</div>
</div>
</div>
<div class="col-md-3">
<div id="chart-13" style="width:100%;">
<div id="chart-13-title"></div>
<div class="reset" style="visibility: hidden;">selected: <span class="filter"></span>
<a href="javascript:chart_13.filterAll();dc.redrawAll();">reset</a>
</div>
</div>
</div>
<div class="col-md-3">
<div id="chart-14" style="width:100%;">
<div id="chart-14-title"></div>
<div class="reset" style="visibility: hidden;">selected: <span class="filter"></span>
<a href="javascript:chart_14.filterAll();dc.redrawAll();">reset</a>
</div>
</div>
</div>
</div>
<!-- Second row of chart -->
<div class="row">
<div class="col-md-3">
<div id="chart-21" style="width:100%;">
<div id="chart-21-title"></div>
<div class="reset" style="visibility: hidden;">selected: <span class="filter"></span>
<a href="javascript:chart_21.filterAll();dc.redrawAll();">reset</a>
</div>
</div>
</div>
<div class="col-md-3">
<div id="chart-22" style="width:100%;">
<div id="chart-22-title"></div>
<div class="reset" style="visibility: hidden;">range: <span class="filter"></span>
<a href="javascript:chart_22.filterAll();dc.redrawAll();">reset</a>
</div>
</div>
</div>
<div class="col-md-3">
<div id="chart-23"style="width:100%;">
<div id="chart-23-title"></div>
<div class="reset" style="visibility: hidden;">selected: <span class="filter"></span>
<a href="javascript:chart_23.filterAll();dc.redrawAll();">reset</a>
</div>
</div>
</div>
<div class="col-md-3">
<div id="chart-24"style="width:100%;">
<div id="chart-24-title"></div>
<div class="reset" style="visibility: hidden;">selected: <span class="filter"></span>
<a href="javascript:chart_24.filterAll();dc.redrawAll();">reset</a>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.9.1/d3.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/crossfilter/1.3.12/crossfilter.js"></script>
<script src="http://unpkg.com/dc@3/dc.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js"></script>
<script type="text/javascript">
'use strict';
dc.config.defaultColors(d3.schemeSet1);
var
chart_11 = dc.barChart("#chart-11"),
chart_12 = dc.barChart("#chart-12"),
chart_13 = dc.barChart("#chart-13"),
chart_21 = dc.barChart("#chart-21"),
chart_22 = dc.barChart("#chart-22"),
chart_23 = dc.barChart("#chart-23"),
data_count = dc.dataCount(".dc-data-count");
d3.csv("https://gist.githubusercontent.com/JasonAizkalns/32ece5c815f9ac5d540c41dc0825bbab/raw/362050300ddcb99f195044c00d9f26b0d7d489ca/data.csv").then(function(data) {
var var_names = ["x", "y", "z", "a", "b", "c"];
$("#chart-11-title").append(["<h5>", var_names[0], "<br>Subtitle</h5>"].join(""));
$("#chart-12-title").append(["<h5>", var_names[1], "<br>Subtitle</h5>"].join(""));
$("#chart-13-title").append(["<h5>", var_names[2], "<br>Subtitle</h5>"].join(""));
$("#chart-21-title").append(["<h5>", var_names[3], "<br>Subtitle</h5>"].join(""));
$("#chart-22-title").append(["<h5>", var_names[4], "<br>Subtitle</h5>"].join(""));
$("#chart-23-title").append(["<h5>", var_names[5], "<br>Subtitle</h5>"].join(""));
var c11_bin = 10,
c12_bin = 10,
c13_bin = 500,
c21_bin = 100,
c22_bin = 20,
c23_bin = 1000;
var ndx = crossfilter(data),
chart_11_dim = ndx.dimension(function(d) { return +d[var_names[0]]; }),
chart_12_dim = ndx.dimension(function(d) { return +d[var_names[1]]; }),
chart_13_dim = ndx.dimension(function(d) { return +d[var_names[2]]; }),
chart_21_dim = ndx.dimension(function(d) { return +d[var_names[3]]; }),
chart_22_dim = ndx.dimension(function(d) { return +d[var_names[4]]; }),
chart_23_dim = ndx.dimension(function(d) { return +d[var_names[5]]; }),
chart_11_grp = chart_11_dim.group(function(d) { return Math.floor(d / c11_bin) * c11_bin }).reduceCount(),
chart_12_grp = chart_12_dim.group(function(d) { return Math.floor(d / c12_bin) * c12_bin }).reduceCount(),
chart_13_grp = chart_13_dim.group(function(d) { return Math.floor(d / c13_bin) * c13_bin }).reduceCount(),
chart_21_grp = chart_21_dim.group(function(d) { return Math.floor(d / c21_bin) * c21_bin }).reduceCount(),
chart_22_grp = chart_22_dim.group(function(d) { return Math.floor(d / c22_bin) * c22_bin }).reduceCount(),
chart_23_grp = chart_23_dim.group(function(d) { return Math.floor(d / c23_bin) * c23_bin }).reduceCount();
var all = ndx.groupAll();
data_count.dimension(ndx)
.group(all);
var chart_11_min = +chart_11_dim.bottom(1)[0][var_names[0]],
chart_11_max = +chart_11_dim.top(1)[0][var_names[0]],
chart_12_min = +chart_12_dim.bottom(1)[0][var_names[1]],
chart_12_max = +chart_12_dim.top(1)[0][var_names[1]],
chart_13_min = +chart_13_dim.bottom(1)[0][var_names[2]],
chart_13_max = +chart_13_dim.top(1)[0][var_names[2]],
chart_21_min = +chart_21_dim.bottom(1)[0][var_names[3]],
chart_21_max = +chart_21_dim.top(1)[0][var_names[3]],
chart_22_min = +chart_22_dim.bottom(1)[0][var_names[4]],
chart_22_max = +chart_22_dim.top(1)[0][var_names[4]],
chart_23_min = +chart_23_dim.bottom(1)[0][var_names[5]],
chart_23_max = +chart_23_dim.top(1)[0][var_names[5]];
var breathing_room = 0.05;
chart_11
.dimension(chart_11_dim)
.group(chart_11_grp)
.round(dc.round.floor)
.alwaysUseRounding(true)
.x(d3.scaleLinear().domain([chart_11_min - ((chart_11_max - chart_11_min) * breathing_room), chart_11_max + ((chart_11_max - chart_11_min) * breathing_room)]))
.xUnits(function(start, end, xDomain) { return (end - start) / c11_bin; })
.controlsUseVisibility(true);
chart_12
.dimension(chart_12_dim)
.group(chart_12_grp)
.round(dc.round.floor)
.alwaysUseRounding(true)
.x(d3.scaleLinear().domain([chart_12_min - ((chart_12_max - chart_12_min) * breathing_room), chart_12_max + ((chart_12_max - chart_12_min) * breathing_room)]))
.xUnits(function(start, end, xDomain) { return (end - start) / c12_bin; })
.controlsUseVisibility(true);
chart_13
.dimension(chart_13_dim)
.group(chart_13_grp)
.round(dc.round.floor)
.alwaysUseRounding(true)
.x(d3.scaleLinear().domain([chart_13_min - ((chart_13_max - chart_13_min) * breathing_room), chart_13_max + ((chart_13_max - chart_13_min) * breathing_room)]))
.xUnits(function(start, end, xDomain) { return (end - start) / c13_bin; })
.controlsUseVisibility(true);
chart_21
.dimension(chart_21_dim)
.group(chart_21_grp)
.round(dc.round.floor)
.alwaysUseRounding(true)
.x(d3.scaleLinear().domain([chart_21_min - ((chart_21_max - chart_21_min) * breathing_room), chart_21_max + ((chart_21_max - chart_21_min) * breathing_room)]))
.xUnits(function(start, end, xDomain) { return (end - start) / c21_bin; })
.controlsUseVisibility(true);
chart_22
.dimension(chart_22_dim)
.group(chart_22_grp)
.round(dc.round.floor)
.alwaysUseRounding(true)
.x(d3.scaleLinear().domain([chart_22_min - ((chart_22_max - chart_22_min) * breathing_room), chart_22_max + ((chart_22_max - chart_22_min) * breathing_room)]))
.xUnits(function(start, end, xDomain) { return (end - start) / c22_bin; })
.controlsUseVisibility(true);
chart_23
.dimension(chart_23_dim)
.group(chart_23_grp)
.round(dc.round.floor)
.alwaysUseRounding(true)
.x(d3.scaleLinear().domain([chart_23_min - ((chart_23_max - chart_23_min) * breathing_room), chart_23_max + ((chart_23_max - chart_23_min) * breathing_room)]))
.xUnits(function(start, end, xDomain) { return (end - start) / c23_bin; })
.controlsUseVisibility(true);
dc.renderAll();
});
</script>
</div>
</body>
</html>
回答1:
So yeah, neither dc.js nor crossfilter directly supports this use case, not that people don't want it.
Crossfilter only supports one active filter and gives you no way to find out what the totals were when no filters were applied.
EDIT: there is now an official example with code cleaned up in response to the follow up code review question. The below discussion still describes the technique well, but the code is less repetitive in the example.
Thanks for the reproducible example to start with. I put your original code in a fiddle.
It's a little tedious, but one way to get the affect you are after is to change each chart into a composite of two bar charts. We'll make the second subchart red and hide it until something is filtered. (More precisely, we'll hide it whenever there is nothing filtered.)
And we'll make the first (blue) subchart always show the initial values, not affected by any filters.
Creating a composite chart looks like this:
var chart_11 = dc.compositeChart("#chart-11"),
chart_12 = dc.compositeChart("#chart-12"),
chart_13 = dc.compositeChart("#chart-13"),
chart_21 = dc.compositeChart("#chart-21"),
chart_22 = dc.compositeChart("#chart-22"),
chart_23 = dc.compositeChart("#chart-23");
chart_11
.compose([
dc.barChart(chart_11)
.dimension(chart_11_dim)
.group(chart_11_grp_copy)
.controlsUseVisibility(true)
,
dc.barChart(chart_11)
.dimension(chart_11_dim)
.group(chart_11_grp)
.colors('red')
.controlsUseVisibility(true)
.brushOn(false)
]);
(Yes it seems you have to apply controlsUseVisibility to every child chart - looks like a bug.)
The heart of the problem is how to make the underlying blue chart not change. We can use a fake group for this. The idea is this object acts like a group except it just returns what the group had on page load:
function static_copy_group(group) {
var all = group.all().map(kv => ({key: kv.key, value: kv.value}));
return {
all: function() {
return all;
}
}
}
var chart_11_grp_copy = static_copy_group(chart_11_grp),
chart_12_grp_copy = static_copy_group(chart_12_grp),
chart_13_grp_copy = static_copy_group(chart_13_grp),
chart_21_grp_copy = static_copy_group(chart_21_grp),
chart_22_grp_copy = static_copy_group(chart_22_grp),
chart_23_grp_copy = static_copy_group(chart_23_grp);
Yes, that's a deep copy of group.all() because crossfilter updates everything in place.
Finally, here's the code to hide the second chart when nothing is filtered:
function any_filters() {
return [chart_11, chart_12, chart_13, chart_21, chart_22, chart_23]
.some(chart => chart.filters().length);
}
function hide_second_chart(chart) {
chart.select('.sub._1')
.attr('visibility', any_filters() ? 'visible' : 'hidden')
}
[chart_11, chart_12, chart_13, chart_21, chart_22, chart_23].forEach(function(chart) {
chart.on('pretransition', hide_second_chart)
})
Example fiddle.
来源：https://stackoverflow.com/questions/55066391/display-original-conditional-brushed-unbrushed-crossfilter-bars-with-dc-js-wit