/* Flot plugin for plotting error bars. Copyright (c) 2007-2014 IOLA and Ole Laursen. Licensed under the MIT license. Error bars are used to show standard deviation and other statistical properties in a plot. * Created by Rui Pereira - rui (dot) pereira (at) gmail (dot) com This plugin allows you to plot error-bars over points. Set "errorbars" inside the points series to the axis name over which there will be error values in your data array (*even* if you do not intend to plot them later, by setting "show: null" on xerr/yerr). The plugin supports these options: series: { points: { errorbars: "x" or "y" or "xy", xerr: { show: null/false or true, asymmetric: null/false or true, upperCap: null or "-" or function, lowerCap: null or "-" or function, color: null or color, radius: null or number }, yerr: { same options as xerr } } } Each data point array is expected to be of the type: "x" [ x, y, xerr ] "y" [ x, y, yerr ] "xy" [ x, y, xerr, yerr ] Where xerr becomes xerr_lower,xerr_upper for the asymmetric error case, and equivalently for yerr. Eg., a datapoint for the "xy" case with symmetric error-bars on X and asymmetric on Y would be: [ x, y, xerr, yerr_lower, yerr_upper ] By default no end caps are drawn. Setting upperCap and/or lowerCap to "-" will draw a small cap perpendicular to the error bar. They can also be set to a user-defined drawing function, with (ctx, x, y, radius) as parameters, as eg. function drawSemiCircle( ctx, x, y, radius ) { ctx.beginPath(); ctx.arc( x, y, radius, 0, Math.PI, false ); ctx.moveTo( x - radius, y ); ctx.lineTo( x + radius, y ); ctx.stroke(); } Color and radius both default to the same ones of the points series if not set. The independent radius parameter on xerr/yerr is useful for the case when we may want to add error-bars to a line, without showing the interconnecting points (with radius: 0), and still showing end caps on the error-bars. shadowSize and lineWidth are derived as well from the points series. */ (function ($) { var options = { series: { points: { errorbars: null, //should be 'x', 'y' or 'xy' xerr: {err: 'x', show: null, asymmetric: null, upperCap: null, lowerCap: null, color: null, radius: null}, yerr: {err: 'y', show: null, asymmetric: null, upperCap: null, lowerCap: null, color: null, radius: null} } } }; function processRawData(plot, series, data, datapoints) { if (!series.points.errorbars) { return; } // x,y values var format = [ { x: true, number: true, required: true }, { y: true, number: true, required: true } ]; var errors = series.points.errorbars; // error bars - first X then Y if (errors === 'x' || errors === 'xy') { // lower / upper error if (series.points.xerr.asymmetric) { format.push({ x: true, number: true, required: true }); format.push({ x: true, number: true, required: true }); } else { format.push({ x: true, number: true, required: true }); } } if (errors === 'y' || errors === 'xy') { // lower / upper error if (series.points.yerr.asymmetric) { format.push({ y: true, number: true, required: true }); format.push({ y: true, number: true, required: true }); } else { format.push({ y: true, number: true, required: true }); } } datapoints.format = format; } function parseErrors(series, i) { var points = series.datapoints.points; // read errors from points array var exl = null, exu = null, eyl = null, eyu = null; var xerr = series.points.xerr, yerr = series.points.yerr; var eb = series.points.errorbars; // error bars - first X if (eb === 'x' || eb === 'xy') { if (xerr.asymmetric) { exl = points[i + 2]; exu = points[i + 3]; if (eb === 'xy') { if (yerr.asymmetric) { eyl = points[i + 4]; eyu = points[i + 5]; } else { eyl = points[i + 4]; } } } else { exl = points[i + 2]; if (eb === 'xy') { if (yerr.asymmetric) { eyl = points[i + 3]; eyu = points[i + 4]; } else { eyl = points[i + 3]; } } } // only Y } else { if (eb === 'y') { if (yerr.asymmetric) { eyl = points[i + 2]; eyu = points[i + 3]; } else { eyl = points[i + 2]; } } } // symmetric errors? if (exu == null) exu = exl; if (eyu == null) eyu = eyl; var errRanges = [exl, exu, eyl, eyu]; // nullify if not showing if (!xerr.show) { errRanges[0] = null; errRanges[1] = null; } if (!yerr.show) { errRanges[2] = null; errRanges[3] = null; } return errRanges; } function drawSeriesErrors(plot, ctx, s) { var points = s.datapoints.points, ps = s.datapoints.pointsize, ax = [s.xaxis, s.yaxis], radius = s.points.radius, err = [s.points.xerr, s.points.yerr], tmp; //sanity check, in case some inverted axis hack is applied to flot var invertX = false; if (ax[0].p2c(ax[0].max) < ax[0].p2c(ax[0].min)) { invertX = true; tmp = err[0].lowerCap; err[0].lowerCap = err[0].upperCap; err[0].upperCap = tmp; } var invertY = false; if (ax[1].p2c(ax[1].min) < ax[1].p2c(ax[1].max)) { invertY = true; tmp = err[1].lowerCap; err[1].lowerCap = err[1].upperCap; err[1].upperCap = tmp; } for (var i = 0; i < s.datapoints.points.length; i += ps) { //parse var errRanges = parseErrors(s, i); //cycle xerr & yerr for (var e = 0; e < err.length; e++) { var minmax = [ax[e].min, ax[e].max]; //draw this error? if (errRanges[e * err.length]) { //data coordinates var x = points[i], y = points[i + 1]; //errorbar ranges var upper = [x, y][e] + errRanges[e * err.length + 1], lower = [x, y][e] - errRanges[e * err.length]; //points outside of the canvas if (err[e].err === 'x') { if (y > ax[1].max || y < ax[1].min || upper < ax[0].min || lower > ax[0].max) { continue; } } if (err[e].err === 'y') { if (x > ax[0].max || x < ax[0].min || upper < ax[1].min || lower > ax[1].max) { continue; } } // prevent errorbars getting out of the canvas var drawUpper = true, drawLower = true; if (upper > minmax[1]) { drawUpper = false; upper = minmax[1]; } if (lower < minmax[0]) { drawLower = false; lower = minmax[0]; } //sanity check, in case some inverted axis hack is applied to flot if ((err[e].err === 'x' && invertX) || (err[e].err === 'y' && invertY)) { //swap coordinates tmp = lower; lower = upper; upper = tmp; tmp = drawLower; drawLower = drawUpper; drawUpper = tmp; tmp = minmax[0]; minmax[0] = minmax[1]; minmax[1] = tmp; } // convert to pixels x = ax[0].p2c(x); y = ax[1].p2c(y); upper = ax[e].p2c(upper); lower = ax[e].p2c(lower); minmax[0] = ax[e].p2c(minmax[0]); minmax[1] = ax[e].p2c(minmax[1]); //same style as points by default var lw = err[e].lineWidth ? err[e].lineWidth : s.points.lineWidth, sw = s.points.shadowSize != null ? s.points.shadowSize : s.shadowSize; //shadow as for points if (lw > 0 && sw > 0) { var w = sw / 2; ctx.lineWidth = w; ctx.strokeStyle = "rgba(0,0,0,0.1)"; drawError(ctx, err[e], x, y, upper, lower, drawUpper, drawLower, radius, w + w / 2, minmax); ctx.strokeStyle = "rgba(0,0,0,0.2)"; drawError(ctx, err[e], x, y, upper, lower, drawUpper, drawLower, radius, w / 2, minmax); } ctx.strokeStyle = err[e].color ? err[e].color : s.color; ctx.lineWidth = lw; //draw it drawError(ctx, err[e], x, y, upper, lower, drawUpper, drawLower, radius, 0, minmax); } } } } function drawError(ctx, err, x, y, upper, lower, drawUpper, drawLower, radius, offset, minmax) { //shadow offset y += offset; upper += offset; lower += offset; // error bar - avoid plotting over circles if (err.err === 'x') { if (upper > x + radius) drawPath(ctx, [[upper, y], [Math.max(x + radius, minmax[0]), y]]); else drawUpper = false; if (lower < x - radius) drawPath(ctx, [[Math.min(x - radius, minmax[1]), y], [lower, y]]); else drawLower = false; } else { if (upper < y - radius) drawPath(ctx, [[x, upper], [x, Math.min(y - radius, minmax[0])]]); else drawUpper = false; if (lower > y + radius) drawPath(ctx, [[x, Math.max(y + radius, minmax[1])], [x, lower]]); else drawLower = false; } //internal radius value in errorbar, allows to plot radius 0 points and still keep proper sized caps //this is a way to get errorbars on lines without visible connecting dots radius = err.radius != null ? err.radius : radius; // upper cap if (drawUpper) { if (err.upperCap === '-') { if (err.err === 'x') drawPath(ctx, [[upper, y - radius], [upper, y + radius]]); else drawPath(ctx, [[x - radius, upper], [x + radius, upper]]); } else if ($.isFunction(err.upperCap)) { if (err.err === 'x') err.upperCap(ctx, upper, y, radius); else err.upperCap(ctx, x, upper, radius); } } // lower cap if (drawLower) { if (err.lowerCap === '-') { if (err.err === 'x') drawPath(ctx, [[lower, y - radius], [lower, y + radius]]); else drawPath(ctx, [[x - radius, lower], [x + radius, lower]]); } else if ($.isFunction(err.lowerCap)) { if (err.err === 'x') err.lowerCap(ctx, lower, y, radius); else err.lowerCap(ctx, x, lower, radius); } } } function drawPath(ctx, pts) { ctx.beginPath(); ctx.moveTo(pts[0][0], pts[0][1]); for (var p = 1; p < pts.length; p++) { ctx.lineTo(pts[p][0], pts[p][1]); } ctx.stroke(); } function draw(plot, ctx) { var plotOffset = plot.getPlotOffset(); ctx.save(); ctx.translate(plotOffset.left, plotOffset.top); $.each(plot.getData(), function (i, s) { if (s.points.errorbars && (s.points.xerr.show || s.points.yerr.show)) { drawSeriesErrors(plot, ctx, s); } }); ctx.restore(); } function init(plot) { plot.hooks.processRawData.push(processRawData); plot.hooks.draw.push(draw); } $.plot.plugins.push({ init: init, options: options, name: 'errorbars', version: '1.0' }); })(jQuery);