text: // MIT License:
  //
  // Copyright (c) 2010-2013, Joe Walnes
  //               2013-2014, Drew Noakes
  //
  // 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.
  
  /**
   * Smoothie Charts - http://smoothiecharts.org/
   * (c) 2010-2013, Joe Walnes
   *     2013-2014, Drew Noakes
   *
   * v1.0: Main charting library, by Joe Walnes
   * v1.1: Auto scaling of axis, by Neil Dunn
   * v1.2: fps (frames per second) option, by Mathias Petterson
   * v1.3: Fix for divide by zero, by Paul Nikitochkin
   * v1.4: Set minimum, top-scale padding, remove timeseries, add optional timer to reset bounds, by Kelley Reynolds
   * v1.5: Set default frames per second to 50... smoother.
   *       .start(), .stop() methods for conserving CPU, by Dmitry Vyal
   *       options.interpolation = 'bezier' or 'line', by Dmitry Vyal
   *       options.maxValue to fix scale, by Dmitry Vyal
   * v1.6: minValue/maxValue will always get converted to floats, by Przemek Matylla
   * v1.7: options.grid.fillStyle may be a transparent color, by Dmitry A. Shashkin
   *       Smooth rescaling, by Kostas Michalopoulos
   * v1.8: Set max length to customize number of live points in the dataset with options.maxDataSetLength, by Krishna Narni
   * v1.9: Display timestamps along the bottom, by Nick and Stev-io
   *       (https://groups.google.com/forum/?fromgroups#!topic/smoothie-charts/-Ywse8FCpKI%5B1-25%5D)
   *       Refactored by Krishna Narni, to support timestamp formatting function
   * v1.10: Switch to requestAnimationFrame, removed the now obsoleted options.fps, by Gergely Imreh
   * v1.11: options.grid.sharpLines option added, by @drewnoakes
   *        Addressed warning seen in Firefox when seriesOption.fillStyle undefined, by @drewnoakes
   * v1.12: Support for horizontalLines added, by @drewnoakes
   *        Support for yRangeFunction callback added, by @drewnoakes
   * v1.13: Fixed typo (#32), by @alnikitich
   * v1.14: Timer cleared when last TimeSeries removed (#23), by @davidgaleano
   *        Fixed diagonal line on chart at start/end of data stream, by @drewnoakes
   * v1.15: Support for npm package (#18), by @dominictarr
   *        Fixed broken removeTimeSeries function (#24) by @davidgaleano
   *        Minor performance and tidying, by @drewnoakes
   * v1.16: Bug fix introduced in v1.14 relating to timer creation/clearance (#23), by @drewnoakes
   *        TimeSeries.append now deals with out-of-order timestamps, and can merge duplicates, by @zacwitte (#12)
   *        Documentation and some local variable renaming for clarity, by @drewnoakes
   * v1.17: Allow control over font size (#10), by @drewnoakes
   *        Timestamp text won't overlap, by @drewnoakes
   * v1.18: Allow control of max/min label precision, by @drewnoakes
   *        Added 'borderVisible' chart option, by @drewnoakes
   *        Allow drawing series with fill but no stroke (line), by @drewnoakes
   * v1.19: Avoid unnecessary repaints, and fixed flicker in old browsers having multiple charts in document (#40), by @asbai
   * v1.20: Add SmoothieChart.getTimeSeriesOptions and SmoothieChart.bringToFront functions, by @drewnoakes
   * v1.21: Add 'step' interpolation mode, by @drewnoakes
   * v1.22: Add support for different pixel ratios. Also add optional y limit formatters, by @copacetic
   * v1.23: Fix bug introduced in v1.22 (#44), by @drewnoakes
   * v1.24: Fix bug introduced in v1.23, re-adding parseFloat to y-axis formatter defaults, by @siggy_sf
   * v1.25: Fix bug seen when adding a data point to TimeSeries which is older than the current data, by @Nking92
   *        Draw time labels on top of series, by @comolosabia
   *        Add TimeSeries.clear function, by @drewnoakes
   * v1.26: Add support for resizing on high device pixel ratio screens, by @copacetic
   * v1.27: Fix bug introduced in v1.26 for non whole number devicePixelRatio values, by @zmbush
   * v1.28: Add 'minValueScale' option, by @megawac
   */
  
  ;(function(exports) {
  
      var Util = {
          extend: function() {
              arguments[0] = arguments[0] || {};
              for (var i = 1; i < arguments.length; i++)
              {
                  for (var key in arguments[i])
                  {
                      if (arguments[i].hasOwnProperty(key))
                      {
                          if (typeof(arguments[i][key]) === 'object') {
                              if (arguments[i][key] instanceof Array) {
                                  arguments[0][key] = arguments[i][key];
                              } else {
                                  arguments[0][key] = Util.extend(arguments[0][key], arguments[i][key]);
                              }
                          } else {
                              arguments[0][key] = arguments[i][key];
                          }
                      }
                  }
              }
              return arguments[0];
          }
      };
  
      /**
       * Initialises a new <code>TimeSeries</code> with optional data options.
       *
       * Options are of the form (defaults shown):
       *
       * <pre>
       * {
     *   resetBounds: true,        // enables/disables automatic scaling of the y-axis
     *   resetBoundsInterval: 3000 // the period between scaling calculations, in millis
     * }
       * </pre>
       *
       * Presentation options for TimeSeries are specified as an argument to <code>SmoothieChart.addTimeSeries</code>.
       *
       * @constructor
       */
      function TimeSeries(options) {
          this.options = Util.extend({}, TimeSeries.defaultOptions, options);
          this.clear();
      }
  
      TimeSeries.defaultOptions = {
          resetBoundsInterval: 3000,
          resetBounds: true
      };
  
      /**
       * Clears all data and state from this TimeSeries object.
       */
      TimeSeries.prototype.clear = function() {
          this.data = [];
          this.maxValue = Number.NaN; // The maximum value ever seen in this TimeSeries.
          this.minValue = Number.NaN; // The minimum value ever seen in this TimeSeries.
      };
  
      /**
       * Recalculate the min/max values for this <code>TimeSeries</code> object.
       *
       * This causes the graph to scale itself in the y-axis.
       */
      TimeSeries.prototype.resetBounds = function() {
          if (this.data.length) {
              // Walk through all data points, finding the min/max value
              this.maxValue = this.data[0][1];
              this.minValue = this.data[0][1];
              for (var i = 1; i < this.data.length; i++) {
                  var value = this.data[i][1];
                  if (value > this.maxValue) {
                      this.maxValue = value;
                  }
                  if (value < this.minValue) {
                      this.minValue = value;
                  }
              }
          } else {
              // No data exists, so set min/max to NaN
              this.maxValue = Number.NaN;
              this.minValue = Number.NaN;
          }
      };
  
      /**
       * Adds a new data point to the <code>TimeSeries</code>, preserving chronological order.
       *
       * @param timestamp the position, in time, of this data point
       * @param value the value of this data point
       * @param sumRepeatedTimeStampValues if <code>timestamp</code> has an exact match in the series, this flag controls
       * whether it is replaced, or the values summed (defaults to false.)
       */
      TimeSeries.prototype.append = function(timestamp, value, sumRepeatedTimeStampValues) {
          // Rewind until we hit an older timestamp
          var i = this.data.length - 1;
          while (i >= 0 && this.data[i][0] > timestamp) {
              i--;
          }
  
          if (i === -1) {
              // This new item is the oldest data
              this.data.splice(0, 0, [timestamp, value]);
          } else if (this.data.length > 0 && this.data[i][0] === timestamp) {
              // Update existing values in the array
              if (sumRepeatedTimeStampValues) {
                  // Sum this value into the existing 'bucket'
                  this.data[i][1] += value;
                  value = this.data[i][1];
              } else {
                  // Replace the previous value
                  this.data[i][1] = value;
              }
          } else if (i < this.data.length - 1) {
              // Splice into the correct position to keep timestamps in order
              this.data.splice(i + 1, 0, [timestamp, value]);
          } else {
              // Add to the end of the array
              this.data.push([timestamp, value]);
          }
  
          this.maxValue = isNaN(this.maxValue) ? value : Math.max(this.maxValue, value);
          this.minValue = isNaN(this.minValue) ? value : Math.min(this.minValue, value);
      };
  
      TimeSeries.prototype.dropOldData = function(oldestValidTime, maxDataSetLength) {
          // We must always keep one expired data point as we need this to draw the
          // line that comes into the chart from the left, but any points prior to that can be removed.
          var removeCount = 0;
          while (this.data.length - removeCount >= maxDataSetLength && this.data[removeCount + 1][0] < oldestValidTime) {
              removeCount++;
          }
          if (removeCount !== 0) {
              this.data.splice(0, removeCount);
          }
      };
  
      /**
       * Initialises a new <code>SmoothieChart</code>.
       *
       * Options are optional, and should be of the form below. Just specify the values you
       * need and the rest will be given sensible defaults as shown:
       *
       * <pre>
       * {
     *   minValue: undefined,                      // specify to clamp the lower y-axis to a given value
     *   maxValue: undefined,                      // specify to clamp the upper y-axis to a given value
     *   maxValueScale: 1,                         // allows proportional padding to be added above the chart. for 10% padding, specify 1.1.
     *   minValueScale: 1,                         // allows proportional padding to be added below the chart. for 10% padding, specify 1.1.
     *   yRangeFunction: undefined,                // function({min: , max: }) { return {min: , max: }; }
     *   scaleSmoothing: 0.125,                    // controls the rate at which y-value zoom animation occurs
     *   millisPerPixel: 20,                       // sets the speed at which the chart pans by
     *   enableDpiScaling: true,                   // support rendering at different DPI depending on the device
     *   yMinFormatter: function(min, precision) { // callback function that formats the min y value label
     *     return parseFloat(min).toFixed(precision);
     *   },
     *   yMaxFormatter: function(max, precision) { // callback function that formats the max y value label
     *     return parseFloat(max).toFixed(precision);
     *   },
     *   maxDataSetLength: 2,
     *   interpolation: 'bezier'                   // one of 'bezier', 'linear', or 'step'
     *   timestampFormatter: null,                 // optional function to format time stamps for bottom of chart
     *                                             // you may use SmoothieChart.timeFormatter, or your own: function(date) { return ''; }
     *   scrollBackwards: false,                   // reverse the scroll direction of the chart
     *   horizontalLines: [],                      // [ { value: 0, color: '#ffffff', lineWidth: 1 } ]
     *   grid:
     *   {
     *     fillStyle: '#000000',                   // the background colour of the chart
     *     lineWidth: 1,                           // the pixel width of grid lines
     *     strokeStyle: '#777777',                 // colour of grid lines
     *     millisPerLine: 1000,                    // distance between vertical grid lines
     *     sharpLines: false,                      // controls whether grid lines are 1px sharp, or softened
     *     verticalSections: 2,                    // number of vertical sections marked out by horizontal grid lines
     *     borderVisible: true                     // whether the grid lines trace the border of the chart or not
     *   },
     *   labels
     *   {
     *     disabled: false,                        // enables/disables labels showing the min/max values
     *     fillStyle: '#ffffff',                   // colour for text of labels,
     *     fontSize: 15,
     *     fontFamily: 'sans-serif',
     *     precision: 2
     *   }
     * }
       * </pre>
       *
       * @constructor
       */
      function SmoothieChart(options) {
          this.options = Util.extend({}, SmoothieChart.defaultChartOptions, options);
          this.seriesSet = [];
          this.currentValueRange = 1;
          this.currentVisMinValue = 0;
          this.lastRenderTimeMillis = 0;
      }
  
      SmoothieChart.defaultChartOptions = {
          millisPerPixel: 20,
          enableDpiScaling: true,
          yMinFormatter: function(min, precision) {
              return parseFloat(min).toFixed(precision);
          },
          yMaxFormatter: function(max, precision) {
              return parseFloat(max).toFixed(precision);
          },
          maxValueScale: 1,
          minValueScale: 1,
          interpolation: 'bezier',
          scaleSmoothing: 0.125,
          maxDataSetLength: 2,
          scrollBackwards: false,
          grid: {
              fillStyle: '#000000',
              strokeStyle: '#777777',
              lineWidth: 1,
              sharpLines: false,
              millisPerLine: 1000,
              verticalSections: 2,
              borderVisible: true
          },
          labels: {
              fillStyle: '#ffffff',
              disabled: false,
              fontSize: 10,
              fontFamily: 'monospace',
              precision: 2
          },
          horizontalLines: []
      };
  
      // Based on http://inspirit.github.com/jsfeat/js/compatibility.js
      SmoothieChart.AnimateCompatibility = (function() {
          var requestAnimationFrame = function(callback, element) {
                  var requestAnimationFrame =
                      window.requestAnimationFrame        ||
                      window.webkitRequestAnimationFrame  ||
                      window.mozRequestAnimationFrame     ||
                      window.oRequestAnimationFrame       ||
                      window.msRequestAnimationFrame      ||
                      function(callback) {
                          return window.setTimeout(function() {
                              callback(new Date().getTime());
                          }, 16);
                      };
                  return requestAnimationFrame.call(window, callback, element);
              },
              cancelAnimationFrame = function(id) {
                  var cancelAnimationFrame =
                      window.cancelAnimationFrame ||
                      function(id) {
                          clearTimeout(id);
                      };
                  return cancelAnimationFrame.call(window, id);
              };
  
          return {
              requestAnimationFrame: requestAnimationFrame,
              cancelAnimationFrame: cancelAnimationFrame
          };
      })();
  
      SmoothieChart.defaultSeriesPresentationOptions = {
          lineWidth: 1,
          strokeStyle: '#ffffff'
      };
  
      /**
       * Adds a <code>TimeSeries</code> to this chart, with optional presentation options.
       *
       * Presentation options should be of the form (defaults shown):
       *
       * <pre>
       * {
     *   lineWidth: 1,
     *   strokeStyle: '#ffffff',
     *   fillStyle: undefined
     * }
       * </pre>
       */
      SmoothieChart.prototype.addTimeSeries = function(timeSeries, options) {
          this.seriesSet.push({timeSeries: timeSeries, options: Util.extend({}, SmoothieChart.defaultSeriesPresentationOptions, options)});
          if (timeSeries.options.resetBounds && timeSeries.options.resetBoundsInterval > 0) {
              timeSeries.resetBoundsTimerId = setInterval(
                  function() {
                      timeSeries.resetBounds();
                  },
                  timeSeries.options.resetBoundsInterval
              );
          }
      };
  
      /**
       * Removes the specified <code>TimeSeries</code> from the chart.
       */
      SmoothieChart.prototype.removeTimeSeries = function(timeSeries) {
          // Find the correct timeseries to remove, and remove it
          var numSeries = this.seriesSet.length;
          for (var i = 0; i < numSeries; i++) {
              if (this.seriesSet[i].timeSeries === timeSeries) {
                  this.seriesSet.splice(i, 1);
                  break;
              }
          }
          // If a timer was operating for that timeseries, remove it
          if (timeSeries.resetBoundsTimerId) {
              // Stop resetting the bounds, if we were
              clearInterval(timeSeries.resetBoundsTimerId);
          }
      };
  
      /**
       * Gets render options for the specified <code>TimeSeries</code>.
       *
       * As you may use a single <code>TimeSeries</code> in multiple charts with different formatting in each usage,
       * these settings are stored in the chart.
       */
      SmoothieChart.prototype.getTimeSeriesOptions = function(timeSeries) {
          // Find the correct timeseries to remove, and remove it
          var numSeries = this.seriesSet.length;
          for (var i = 0; i < numSeries; i++) {
              if (this.seriesSet[i].timeSeries === timeSeries) {
                  return this.seriesSet[i].options;
              }
          }
      };
  
      /**
       * Brings the specified <code>TimeSeries</code> to the top of the chart. It will be rendered last.
       */
      SmoothieChart.prototype.bringToFront = function(timeSeries) {
          // Find the correct timeseries to remove, and remove it
          var numSeries = this.seriesSet.length;
          for (var i = 0; i < numSeries; i++) {
              if (this.seriesSet[i].timeSeries === timeSeries) {
                  var set = this.seriesSet.splice(i, 1);
                  this.seriesSet.push(set[0]);
                  break;
              }
          }
      };
  
      /**
       * Instructs the <code>SmoothieChart</code> to start rendering to the provided canvas, with specified delay.
       *
       * @param canvas the target canvas element
       * @param delayMillis an amount of time to wait before a data point is shown. This can prevent the end of the series
       * from appearing on screen, with new values flashing into view, at the expense of some latency.
       */
      SmoothieChart.prototype.streamTo = function(canvas, delayMillis) {
          this.canvas = canvas;
          this.delay = delayMillis;
          this.start();
      };
  
      /**
       * Make sure the canvas has the optimal resolution for the device's pixel ratio.
       */
      SmoothieChart.prototype.resize = function() {
          // TODO this function doesn't handle the value of enableDpiScaling changing during execution
          if (!this.options.enableDpiScaling || !window || window.devicePixelRatio === 1)
              return;
  
          var dpr = window.devicePixelRatio;
          var width = parseInt(this.canvas.getAttribute('width'));
          var height = parseInt(this.canvas.getAttribute('height'));
  
          if (!this.originalWidth || (Math.floor(this.originalWidth * dpr) !== width)) {
              this.originalWidth = width;
              this.canvas.setAttribute('width', (Math.floor(width * dpr)).toString());
              this.canvas.style.width = width + 'px';
              this.canvas.getContext('2d').scale(dpr, dpr);
          }
  
          if (!this.originalHeight || (Math.floor(this.originalHeight * dpr) !== height)) {
              this.originalHeight = height;
              this.canvas.setAttribute('height', (Math.floor(height * dpr)).toString());
              this.canvas.style.height = height + 'px';
              this.canvas.getContext('2d').scale(dpr, dpr);
          }
      };
  
      /**
       * Starts the animation of this chart.
       */
      SmoothieChart.prototype.start = function() {
          if (this.frame) {
              // We're already running, so just return
              return;
          }
  
          // Renders a frame, and queues the next frame for later rendering
          var animate = function() {
              this.frame = SmoothieChart.AnimateCompatibility.requestAnimationFrame(function() {
                  this.render();
                  animate();
              }.bind(this));
          }.bind(this);
  
          animate();
      };
  
      /**
       * Stops the animation of this chart.
       */
      SmoothieChart.prototype.stop = function() {
          if (this.frame) {
              SmoothieChart.AnimateCompatibility.cancelAnimationFrame(this.frame);
              delete this.frame;
          }
      };
  
      SmoothieChart.prototype.updateValueRange = function() {
          // Calculate the current scale of the chart, from all time series.
          var chartOptions = this.options,
              chartMaxValue = Number.NaN,
              chartMinValue = Number.NaN;
  
          for (var d = 0; d < this.seriesSet.length; d++) {
              // TODO(ndunn): We could calculate / track these values as they stream in.
              var timeSeries = this.seriesSet[d].timeSeries;
              if (!isNaN(timeSeries.maxValue)) {
                  chartMaxValue = !isNaN(chartMaxValue) ? Math.max(chartMaxValue, timeSeries.maxValue) : timeSeries.maxValue;
              }
  
              if (!isNaN(timeSeries.minValue)) {
                  chartMinValue = !isNaN(chartMinValue) ? Math.min(chartMinValue, timeSeries.minValue) : timeSeries.minValue;
              }
          }
  
          // Scale the chartMaxValue to add padding at the top if required
          if (chartOptions.maxValue != null) {
              chartMaxValue = chartOptions.maxValue;
          } else {
              chartMaxValue *= chartOptions.maxValueScale;
          }
  
          // Set the minimum if we've specified one
          if (chartOptions.minValue != null) {
              chartMinValue = chartOptions.minValue;
          } else {
              chartMinValue -= Math.abs(chartMinValue * chartOptions.minValueScale - chartMinValue);
          }
  
          // If a custom range function is set, call it
          if (this.options.yRangeFunction) {
              var range = this.options.yRangeFunction({min: chartMinValue, max: chartMaxValue});
              chartMinValue = range.min;
              chartMaxValue = range.max;
          }
  
          if (!isNaN(chartMaxValue) && !isNaN(chartMinValue)) {
              var targetValueRange = chartMaxValue - chartMinValue;
              var valueRangeDiff = (targetValueRange - this.currentValueRange);
              var minValueDiff = (chartMinValue - this.currentVisMinValue);
              this.isAnimatingScale = Math.abs(valueRangeDiff) > 0.1 || Math.abs(minValueDiff) > 0.1;
              this.currentValueRange += chartOptions.scaleSmoothing * valueRangeDiff;
              this.currentVisMinValue += chartOptions.scaleSmoothing * minValueDiff;
          }
  
          this.valueRange = { min: chartMinValue, max: chartMaxValue };
      };
  
      SmoothieChart.prototype.render = function(canvas, time) {
          var nowMillis = new Date().getTime();
  
          if (!this.isAnimatingScale) {
              // We're not animating. We can use the last render time and the scroll speed to work out whether
              // we actually need to paint anything yet. If not, we can return immediately.
  
              // Render at least every 1/6th of a second. The canvas may be resized, which there is
              // no reliable way to detect.
              var maxIdleMillis = Math.min(1000/6, this.options.millisPerPixel);
  
              if (nowMillis - this.lastRenderTimeMillis < maxIdleMillis) {
                  return;
              }
          }
  
          this.resize();
  
          this.lastRenderTimeMillis = nowMillis;
  
          canvas = canvas || this.canvas;
          time = time || nowMillis - (this.delay || 0);
  
          // Round time down to pixel granularity, so motion appears smoother.
          time -= time % this.options.millisPerPixel;
  
          var context = canvas.getContext('2d'),
              chartOptions = this.options,
              dimensions = { top: 0, left: 0, width: canvas.clientWidth, height: canvas.clientHeight },
          // Calculate the threshold time for the oldest data points.
              oldestValidTime = time - (dimensions.width * chartOptions.millisPerPixel),
              valueToYPixel = function(value) {
                  var offset = value - this.currentVisMinValue;
                  return this.currentValueRange === 0
                      ? dimensions.height
                      : dimensions.height - (Math.round((offset / this.currentValueRange) * dimensions.height));
              }.bind(this),
              timeToXPixel = function(t) {
                  if(chartOptions.scrollBackwards) {
                      return Math.round((time - t) / chartOptions.millisPerPixel);
                  }
                  return Math.round(dimensions.width - ((time - t) / chartOptions.millisPerPixel));
              };
  
          this.updateValueRange();
  
          context.font = chartOptions.labels.fontSize + 'px ' + chartOptions.labels.fontFamily;
  
          // Save the state of the canvas context, any transformations applied in this method
          // will get removed from the stack at the end of this method when .restore() is called.
          context.save();
  
          // Move the origin.
          context.translate(dimensions.left, dimensions.top);
  
          // Create a clipped rectangle - anything we draw will be constrained to this rectangle.
          // This prevents the occasional pixels from curves near the edges overrunning and creating
          // screen cheese (that phrase should need no explanation).
          context.beginPath();
          context.rect(0, 0, dimensions.width, dimensions.height);
          context.clip();
  
          // Clear the working area.
          context.save();
          context.fillStyle = chartOptions.grid.fillStyle;
          context.clearRect(0, 0, dimensions.width, dimensions.height);
          context.fillRect(0, 0, dimensions.width, dimensions.height);
          context.restore();
  
          // Grid lines...
          context.save();
          context.lineWidth = chartOptions.grid.lineWidth;
          context.strokeStyle = chartOptions.grid.strokeStyle;
          // Vertical (time) dividers.
          if (chartOptions.grid.millisPerLine > 0) {
              context.beginPath();
              for (var t = time - (time % chartOptions.grid.millisPerLine);
                   t >= oldestValidTime;
                   t -= chartOptions.grid.millisPerLine) {
                  var gx = timeToXPixel(t);
                  if (chartOptions.grid.sharpLines) {
                      gx -= 0.5;
                  }
                  context.moveTo(gx, 0);
                  context.lineTo(gx, dimensions.height);
              }
              context.stroke();
              context.closePath();
          }
  
          // Horizontal (value) dividers.
          for (var v = 1; v < chartOptions.grid.verticalSections; v++) {
              var gy = Math.round(v * dimensions.height / chartOptions.grid.verticalSections);
              if (chartOptions.grid.sharpLines) {
                  gy -= 0.5;
              }
              context.beginPath();
              context.moveTo(0, gy);
              context.lineTo(dimensions.width, gy);
              context.stroke();
              context.closePath();
          }
          // Bounding rectangle.
          if (chartOptions.grid.borderVisible) {
              context.beginPath();
              context.strokeRect(0, 0, dimensions.width, dimensions.height);
              context.closePath();
          }
          context.restore();
  
          // Draw any horizontal lines...
          if (chartOptions.horizontalLines && chartOptions.horizontalLines.length) {
              for (var hl = 0; hl < chartOptions.horizontalLines.length; hl++) {
                  var line = chartOptions.horizontalLines[hl],
                      hly = Math.round(valueToYPixel(line.value)) - 0.5;
                  context.strokeStyle = line.color || '#ffffff';
                  context.lineWidth = line.lineWidth || 1;
                  context.beginPath();
                  context.moveTo(0, hly);
                  context.lineTo(dimensions.width, hly);
                  context.stroke();
                  context.closePath();
              }
          }
  
          // For each data set...
          for (var d = 0; d < this.seriesSet.length; d++) {
              context.save();
              var timeSeries = this.seriesSet[d].timeSeries,
                  dataSet = timeSeries.data,
                  seriesOptions = this.seriesSet[d].options;
  
              // Delete old data that's moved off the left of the chart.
              timeSeries.dropOldData(oldestValidTime, chartOptions.maxDataSetLength);
  
              // Set style for this dataSet.
              context.lineWidth = seriesOptions.lineWidth;
              context.strokeStyle = seriesOptions.strokeStyle;
              // Draw the line...
              context.beginPath();
              // Retain lastX, lastY for calculating the control points of bezier curves.
              var firstX = 0, lastX = 0, lastY = 0;
              for (var i = 0; i < dataSet.length && dataSet.length !== 1; i++) {
                  var x = timeToXPixel(dataSet[i][0]),
                      y = valueToYPixel(dataSet[i][1]);
  
                  if (i === 0) {
                      firstX = x;
                      context.moveTo(x, y);
                  } else {
                      switch (chartOptions.interpolation) {
                          case "linear":
                          case "line": {
                              context.lineTo(x,y);
                              break;
                          }
                          case "bezier":
                          default: {
                              // Great explanation of Bezier curves: http://en.wikipedia.org/wiki/Bezier_curve#Quadratic_curves
                              //
                              // Assuming A was the last point in the line plotted and B is the new point,
                              // we draw a curve with control points P and Q as below.
                              //
                              // A---P
                              //     |
                              //     |
                              //     |
                              //     Q---B
                              //
                              // Importantly, A and P are at the same y coordinate, as are B and Q. This is
                              // so adjacent curves appear to flow as one.
                              //
                              context.bezierCurveTo( // startPoint (A) is implicit from last iteration of loop
                                  Math.round((lastX + x) / 2), lastY, // controlPoint1 (P)
                                  Math.round((lastX + x)) / 2, y, // controlPoint2 (Q)
                                  x, y); // endPoint (B)
                              break;
                          }
                          case "step": {
                              context.lineTo(x,lastY);
                              context.lineTo(x,y);
                              break;
                          }
                      }
                  }
  
                  lastX = x; lastY = y;
              }
  
              if (dataSet.length > 1) {
                  if (seriesOptions.fillStyle) {
                      // Close up the fill region.
                      context.lineTo(dimensions.width + seriesOptions.lineWidth + 1, lastY);
                      context.lineTo(dimensions.width + seriesOptions.lineWidth + 1, dimensions.height + seriesOptions.lineWidth + 1);
                      context.lineTo(firstX, dimensions.height + seriesOptions.lineWidth);
                      context.fillStyle = seriesOptions.fillStyle;
                      context.fill();
                  }
  
                  if (seriesOptions.strokeStyle && seriesOptions.strokeStyle !== 'none') {
                      context.stroke();
                  }
                  context.closePath();
              }
              context.restore();
          }
  
          // Draw the axis values on the chart.
          if (!chartOptions.labels.disabled && !isNaN(this.valueRange.min) && !isNaN(this.valueRange.max)) {
              var maxValueString = chartOptions.yMaxFormatter(this.valueRange.max, chartOptions.labels.precision),
                  minValueString = chartOptions.yMinFormatter(this.valueRange.min, chartOptions.labels.precision),
                  labelPos = chartOptions.scrollBackwards ? 0 : dimensions.width - context.measureText(maxValueString).width - 2;
              context.fillStyle = chartOptions.labels.fillStyle;
              context.fillText(maxValueString, labelPos, chartOptions.labels.fontSize);
              context.fillText(minValueString, labelPos, dimensions.height - 2);
          }
  
          // Display timestamps along x-axis at the bottom of the chart.
          if (chartOptions.timestampFormatter && chartOptions.grid.millisPerLine > 0) {
              var textUntilX = chartOptions.scrollBackwards
                  ? context.measureText(minValueString).width
                  : dimensions.width - context.measureText(minValueString).width + 4;
              for (var t = time - (time % chartOptions.grid.millisPerLine);
                   t >= oldestValidTime;
                   t -= chartOptions.grid.millisPerLine) {
                  var gx = timeToXPixel(t);
                  // Only draw the timestamp if it won't overlap with the previously drawn one.
                  if ((!chartOptions.scrollBackwards && gx < textUntilX) || (chartOptions.scrollBackwards && gx > textUntilX))  {
                      // Formats the timestamp based on user specified formatting function
                      // SmoothieChart.timeFormatter function above is one such formatting option
                      var tx = new Date(t),
                          ts = chartOptions.timestampFormatter(tx),
                          tsWidth = context.measureText(ts).width;
  
                      textUntilX = chartOptions.scrollBackwards
                          ? gx + tsWidth + 2
                          : gx - tsWidth - 2;
  
                      context.fillStyle = chartOptions.labels.fillStyle;
                      if(chartOptions.scrollBackwards) {
                          context.fillText(ts, gx, dimensions.height - 2);
                      } else {
                          context.fillText(ts, gx - tsWidth, dimensions.height - 2);
                      }
                  }
              }
          }
  
          context.restore(); // See .save() above.
      };
  
      // Sample timestamp formatting function
      SmoothieChart.timeFormatter = function(date) {
          function pad2(number) { return (number < 10 ? '0' : '') + number }
          return pad2(date.getHours()) + ':' + pad2(date.getMinutes()) + ':' + pad2(date.getSeconds());
      };
  
      exports.TimeSeries = TimeSeries;
      exports.SmoothieChart = SmoothieChart;
  
  })(typeof exports === 'undefined' ? this : exports);
  
  