/* Flot plugin for stacking data sets rather than overlyaing them.
|
|
Copyright (c) 2007-2014 IOLA and Ole Laursen.
|
Licensed under the MIT license.
|
|
The plugin assumes the data is sorted on x (or y if stacking horizontally).
|
For line charts, it is assumed that if a line has an undefined gap (from a
|
null point), then the line above it should have the same gap - insert zeros
|
instead of "null" if you want another behaviour. This also holds for the start
|
and end of the chart. Note that stacking a mix of positive and negative values
|
in most instances doesn't make sense (so it looks weird).
|
|
Two or more series are stacked when their "stack" attribute is set to the same
|
key (which can be any number or string or just "true"). To specify the default
|
stack, you can set the stack option like this:
|
|
series: {
|
stack: null/false, true, or a key (number/string)
|
}
|
|
You can also specify it for a single series, like this:
|
|
$.plot( $("#placeholder"), [{
|
data: [ ... ],
|
stack: true
|
}])
|
|
The stacking order is determined by the order of the data series in the array
|
(later series end up on top of the previous).
|
|
Internally, the plugin modifies the datapoints in each series, adding an
|
offset to the y value. For line series, extra data points are inserted through
|
interpolation. If there's a second y value, it's also adjusted (e.g for bar
|
charts or filled areas).
|
|
*/
|
|
(function ($) {
|
var options = {
|
series: { stack: null } // or number/string
|
};
|
|
function init(plot) {
|
function findMatchingSeries(s, allseries) {
|
var res = null;
|
for (var i = 0; i < allseries.length; ++i) {
|
if (s == allseries[i])
|
break;
|
|
if (allseries[i].stack == s.stack)
|
res = allseries[i];
|
}
|
|
return res;
|
}
|
|
function stackData(plot, s, datapoints) {
|
if (s.stack == null || s.stack === false)
|
return;
|
|
var other = findMatchingSeries(s, plot.getData());
|
if (!other)
|
return;
|
|
var ps = datapoints.pointsize,
|
points = datapoints.points,
|
otherps = other.datapoints.pointsize,
|
otherpoints = other.datapoints.points,
|
newpoints = [],
|
px, py, intery, qx, qy, bottom,
|
withlines = s.lines.show,
|
horizontal = s.bars.horizontal,
|
withbottom = ps > 2 && (horizontal ? datapoints.format[2].x : datapoints.format[2].y),
|
withsteps = withlines && s.lines.steps,
|
fromgap = true,
|
keyOffset = horizontal ? 1 : 0,
|
accumulateOffset = horizontal ? 0 : 1,
|
i = 0, j = 0, l, m;
|
|
while (true) {
|
if (i >= points.length)
|
break;
|
|
l = newpoints.length;
|
|
if (points[i] == null) {
|
// copy gaps
|
for (m = 0; m < ps; ++m)
|
newpoints.push(points[i + m]);
|
i += ps;
|
}
|
else if (j >= otherpoints.length) {
|
// for lines, we can't use the rest of the points
|
if (!withlines) {
|
for (m = 0; m < ps; ++m)
|
newpoints.push(points[i + m]);
|
}
|
i += ps;
|
}
|
else if (otherpoints[j] == null) {
|
// oops, got a gap
|
for (m = 0; m < ps; ++m)
|
newpoints.push(null);
|
fromgap = true;
|
j += otherps;
|
}
|
else {
|
// cases where we actually got two points
|
px = points[i + keyOffset];
|
py = points[i + accumulateOffset];
|
qx = otherpoints[j + keyOffset];
|
qy = otherpoints[j + accumulateOffset];
|
bottom = 0;
|
|
if (px == qx) {
|
for (m = 0; m < ps; ++m)
|
newpoints.push(points[i + m]);
|
|
newpoints[l + accumulateOffset] += qy;
|
bottom = qy;
|
|
i += ps;
|
j += otherps;
|
}
|
else if (px > qx) {
|
// we got past point below, might need to
|
// insert interpolated extra point
|
if (withlines && i > 0 && points[i - ps] != null) {
|
intery = py + (points[i - ps + accumulateOffset] - py) * (qx - px) / (points[i - ps + keyOffset] - px);
|
newpoints.push(qx);
|
newpoints.push(intery + qy);
|
for (m = 2; m < ps; ++m)
|
newpoints.push(points[i + m]);
|
bottom = qy;
|
}
|
|
j += otherps;
|
}
|
else { // px < qx
|
if (fromgap && withlines) {
|
// if we come from a gap, we just skip this point
|
i += ps;
|
continue;
|
}
|
|
for (m = 0; m < ps; ++m)
|
newpoints.push(points[i + m]);
|
|
// we might be able to interpolate a point below,
|
// this can give us a better y
|
if (withlines && j > 0 && otherpoints[j - otherps] != null)
|
bottom = qy + (otherpoints[j - otherps + accumulateOffset] - qy) * (px - qx) / (otherpoints[j - otherps + keyOffset] - qx);
|
|
newpoints[l + accumulateOffset] += bottom;
|
|
i += ps;
|
}
|
|
fromgap = false;
|
|
if (l != newpoints.length && withbottom)
|
newpoints[l + 2] += bottom;
|
}
|
|
// maintain the line steps invariant
|
if (withsteps && l != newpoints.length && l > 0
|
&& newpoints[l] != null
|
&& newpoints[l] != newpoints[l - ps]
|
&& newpoints[l + 1] != newpoints[l - ps + 1]) {
|
for (m = 0; m < ps; ++m)
|
newpoints[l + ps + m] = newpoints[l + m];
|
newpoints[l + 1] = newpoints[l - ps + 1];
|
}
|
}
|
|
datapoints.points = newpoints;
|
}
|
|
plot.hooks.processDatapoints.push(stackData);
|
}
|
|
$.plot.plugins.push({
|
init: init,
|
options: options,
|
name: 'stack',
|
version: '1.2'
|
});
|
})(jQuery);
|
