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MichaelZinsmaier-CurvedLines/curvedLines.js

455 lines
14 KiB
JavaScript

/* The MIT License
Copyright (c) 2011 by Michael Zinsmaier and nergal.dev
Copyright (c) 2012 by Thomas Ritou
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
/*
____________________________________________________
what it is:
____________________________________________________
curvedLines is a plugin for flot, that tries to display lines in a smoother way.
This is achieved through adding of more data points. The plugin is a data processor and can thus be used
in combination with standard line / point rendering options.
=> 1) with large data sets you may get trouble
=> 2) if you want to display the points too, you have to plot them as 2nd data series over the lines
&& 3) consecutive x data points are not allowed to have the same value
Feel free to further improve the code
____________________________________________________
how to use it:
____________________________________________________
var d1 = [[5,5],[7,3],[9,12]];
var options = { series: { curvedLines: { active: true }}};
$.plot($("#placeholder"), [{data = d1, lines: { show: true}, curvedLines: {apply: true}}], options);
_____________________________________________________
options:
_____________________________________________________
active: bool true => plugin can be used
apply: bool true => series will be drawn as curved line
deprecated options from flot prior to 1.0.0:
------------------------------------------------
legacyOverride bool true => use old default OR
legacyOverride optionArray
{
fit: bool true => forces the max,mins of the curve to be on the datapoints
curvePointFactor int defines how many "virtual" points are used per "real" data point to
emulate the curvedLines (points total = real points * curvePointFactor)
fitPointDist: int defines the x axis distance of the additional two points that are used
} to enforce the min max condition.
*/
/*
* v0.1 initial commit
* v0.15 negative values should work now (outcommented a negative -> 0 hook hope it does no harm)
* v0.2 added fill option (thanks to monemihir) and multi axis support (thanks to soewono effendi)
* v0.3 improved saddle handling and added basic handling of Dates
* v0.4 rewritten fill option (thomas ritou) mostly from original flot code (now fill between points rather than to graph bottom), corrected fill Opacity bug
* v0.5 rewritten instead of implementing a own draw function CurvedLines is now based on the processDatapoints flot hook (credits go to thomas ritou).
* This change breakes existing code however CurvedLines are now just many tiny straight lines to flot and therefore all flot lines options (like gradient fill,
* shadow) are now supported out of the box
* v0.6 flot 0.8 compatibility and some bug fixes
* v0.6.x changed versioning schema
*
* v1.0.0 API Break marked existing implementation/options as deprecated
*/
(function($) {
var options = {
series : {
curvedLines : {
active : false,
apply : false,
monotonicFit : false,
tension : 0.0,
nrSplinePoints : 20,
legacyOverride : undefined
}
}
};
function init(plot) {
plot.hooks.processOptions.push(processOptions);
//if the plugin is active register processDatapoints method
function processOptions(plot, options) {
if (options.series.curvedLines.active) {
plot.hooks.processDatapoints.unshift(processDatapoints);
}
}
//only if the plugin is active
function processDatapoints(plot, series, datapoints) {
var nrPoints = datapoints.points.length / datapoints.pointsize;
var EPSILON = 0.005;
if (series.curvedLines.apply == true && series.originSeries === undefined && nrPoints > (1 + EPSILON)) {
if (series.lines.fill) {
var pointsTop = calculateCurvePoints(datapoints, series.curvedLines, 1);
var pointsBottom = calculateCurvePoints(datapoints, series.curvedLines, 2);
//flot makes sure for us that we've got a second y point if fill is true !
//Merge top and bottom curve
datapoints.pointsize = 3;
datapoints.points = [];
var j = 0;
var k = 0;
var i = 0;
var ps = 2;
while (i < pointsTop.length || j < pointsBottom.length) {
if (pointsTop[i] == pointsBottom[j]) {
datapoints.points[k] = pointsTop[i];
datapoints.points[k + 1] = pointsTop[i + 1];
datapoints.points[k + 2] = pointsBottom[j + 1];
j += ps;
i += ps;
} else if (pointsTop[i] < pointsBottom[j]) {
datapoints.points[k] = pointsTop[i];
datapoints.points[k + 1] = pointsTop[i + 1];
datapoints.points[k + 2] = k > 0 ? datapoints.points[k - 1] : null;
i += ps;
} else {
datapoints.points[k] = pointsBottom[j];
datapoints.points[k + 1] = k > 1 ? datapoints.points[k - 2] : null;
datapoints.points[k + 2] = pointsBottom[j + 1];
j += ps;
}
k += 3;
}
} else if (series.lines.lineWidth > 0) {
datapoints.points = calculateCurvePoints(datapoints, series.curvedLines, 1);
datapoints.pointsize = 2;
}
}
}
function calculateCurvePoints(datapoints, curvedLinesOptions, yPos) {
if ( typeof curvedLinesOptions.legacyOverride != 'undefined' && curvedLinesOptions.legacyOverride != false) {
var defaultOptions = {
fit : false,
curvePointFactor : 20,
fitPointDist : undefined
};
var legacyOptions = jQuery.extend(defaultOptions, curvedLinesOptions.legacyOverride);
return calculateLegacyCurvePoints(datapoints, legacyOptions, yPos);
}
return calculateSplineCurvePoints(datapoints, curvedLinesOptions, yPos);
}
function calculateSplineCurvePoints(datapoints, curvedLinesOptions, yPos) {
var points = datapoints.points;
var ps = datapoints.pointsize;
//create interpolant fuction
var splines = createHermiteSplines(datapoints, curvedLinesOptions, yPos);
var result = [];
//sample the function
// (the result is intependent from the input data =>
// it is ok to alter the input after this method)
var j = 0;
for (var i = 0; i < points.length - ps; i += ps) {
var curX = i;
var curY = i + yPos;
var xStart = points[curX];
var xEnd = points[curX + ps];
var xStep = (xEnd - xStart) / Number(curvedLinesOptions.nrSplinePoints);
//add point
result.push(points[curX]);
result.push(points[curY]);
//add curve point
for (var x = (xStart += xStep); x < xEnd; x += xStep) {
result.push(x);
result.push(splines[j](x));
}
j++;
}
//add last point
result.push(points[points.length - ps]);
result.push(points[points.length - ps + yPos]);
return result;
}
function createHermiteSplines(datapoints, curvedLinesOptions, yPos) {
var points = datapoints.points;
var ps = datapoints.pointsize;
// Get consecutive differences and slopes
var dxs = [];
var dys = [];
var ms = [];
for (var i = 0; i < points.length - ps; i += ps) {
var curX = i;
var curY = i + yPos;
var dx = points[curX + ps] - points[curX];
var dy = points[curY + ps] - points[curY];
dxs.push(dx);
dys.push(dy);
ms.push(dy / dx);
}
// Get degree-1 coefficients
var c1s = [ms[0]];
if (curvedLinesOptions.monotonicFit) {
// Fritsch Carlson
for (var i = 0; i < dxs.length - 1; i++) {
var m = ms[i];
var mNext = ms[i + 1];
if (m * mNext <= 0) {
c1s.push(0);
} else {
var dx = dxs[i];
var dxNext = dxs[i + 1];
var common = dx + dxNext;
c1s.push(3 * common / ((common + dxNext) / m + (common + dx) / mNext));
}
}
} else {
// Cardinal spline with t € [0,1]
// Catmull-Rom for t = 0
for (var i = ps; i < points.length - ps; i += ps) {
var curX = i;
var curY = i + yPos;
c1s.push(Number(curvedLinesOptions.tension) * (points[curY + ps] - points[curY - ps]) / (points[curX + ps] - points[curX - ps]));
}
}
c1s.push(ms[ms.length - 1]);
// Get degree-2 and degree-3 coefficients
var c2s = [], c3s = [];
for ( i = 0; i < c1s.length - 1; i++) {
var c1 = c1s[i];
var m = ms[i];
var invDx = 1 / dxs[i];
var common = c1 + c1s[i + 1] - m - m;
c2s.push((m - c1 - common) * invDx);
c3s.push(common * invDx * invDx);
}
//create functions with captured parameters
var ret = [];
for (var i = 0; i < c1s.length - 1; i ++) {
var spline = function (x0, a, b, c, d) {
// spline for a segment
return function (x) {
var diff = x - x0;
var diffSq = diff * diff;
return a * diff + b * diffSq + c * diff * diffSq + d;
};
};
ret.push(spline(points[i * ps], c1s[i], c2s[i], c3s[i], points[i * ps + yPos]));
}
return ret;
};
//no real idea whats going on here code mainly from https://code.google.com/p/flot/issues/detail?id=226
//if fit option is selected additional datapoints get inserted before the curve calculations in nergal.dev s code.
function calculateLegacyCurvePoints(datapoints, curvedLinesOptions, yPos) {
var points = datapoints.points;
var ps = datapoints.pointsize;
var num = Number(curvedLinesOptions.curvePointFactor) * (points.length / ps);
var xdata = new Array;
var ydata = new Array;
var curX = -1;
var curY = -1;
var j = 0;
if (curvedLinesOptions.fit) {
//insert a point before and after the "real" data point to force the line
//to have a max,min at the data point.
var fpDist;
if ( typeof curvedLinesOptions.fitPointDist == 'undefined') {
//estimate it
var minX = points[0];
var maxX = points[points.length - ps];
fpDist = (maxX - minX) / (500 * 100);
//x range / (estimated pixel length of placeholder * factor)
} else {
//use user defined value
fpDist = Number(curvedLinesOptions.fitPointDist);
}
for (var i = 0; i < points.length; i += ps) {
var frontX;
var backX;
curX = i;
curY = i + yPos;
//add point X s
frontX = points[curX] - fpDist;
backX = points[curX] + fpDist;
var factor = 2;
while (frontX == points[curX] || backX == points[curX]) {
//inside the ulp
frontX = points[curX] - (fpDist * factor);
backX = points[curX] + (fpDist * factor);
factor++;
}
//add curve points
xdata[j] = frontX;
ydata[j] = points[curY];
j++;
xdata[j] = points[curX];
ydata[j] = points[curY];
j++;
xdata[j] = backX;
ydata[j] = points[curY];
j++;
}
} else {
//just use the datapoints
for (var i = 0; i < points.length; i += ps) {
curX = i;
curY = i + yPos;
xdata[j] = points[curX];
ydata[j] = points[curY];
j++;
}
}
var n = xdata.length;
var y2 = new Array();
var delta = new Array();
y2[0] = 0;
y2[n - 1] = 0;
delta[0] = 0;
for (var i = 1; i < n - 1; ++i) {
var d = (xdata[i + 1] - xdata[i - 1]);
if (d == 0) {
//point before current point and after current point need some space in between
return [];
}
var s = (xdata[i] - xdata[i - 1]) / d;
var p = s * y2[i - 1] + 2;
y2[i] = (s - 1) / p;
delta[i] = (ydata[i + 1] - ydata[i]) / (xdata[i + 1] - xdata[i]) - (ydata[i] - ydata[i - 1]) / (xdata[i] - xdata[i - 1]);
delta[i] = (6 * delta[i] / (xdata[i + 1] - xdata[i - 1]) - s * delta[i - 1]) / p;
}
for (var j = n - 2; j >= 0; --j) {
y2[j] = y2[j] * y2[j + 1] + delta[j];
}
// xmax - xmin / #points
var step = (xdata[n - 1] - xdata[0]) / (num - 1);
var xnew = new Array;
var ynew = new Array;
var result = new Array;
xnew[0] = xdata[0];
ynew[0] = ydata[0];
result.push(xnew[0]);
result.push(ynew[0]);
for ( j = 1; j < num; ++j) {
//new x point (sampling point for the created curve)
xnew[j] = xnew[0] + j * step;
var max = n - 1;
var min = 0;
while (max - min > 1) {
var k = Math.round((max + min) / 2);
if (xdata[k] > xnew[j]) {
max = k;
} else {
min = k;
}
}
//found point one to the left and one to the right of generated new point
var h = (xdata[max] - xdata[min]);
if (h == 0) {
//similar to above two points from original x data need some space between them
return [];
}
var a = (xdata[max] - xnew[j]) / h;
var b = (xnew[j] - xdata[min]) / h;
ynew[j] = a * ydata[min] + b * ydata[max] + ((a * a * a - a) * y2[min] + (b * b * b - b) * y2[max]) * (h * h) / 6;
result.push(xnew[j]);
result.push(ynew[j]);
}
return result;
}
}//end init
$.plot.plugins.push({
init : init,
options : options,
name : 'curvedLines',
version : '1.1.0'
});
})(jQuery);