Error:
ExampleBrowser.csproj(118,5): error MSB4044: The "PepitaGet.RestorePackagesTask" task was not given a value for the required parameter "ProjectDirectory".

The relative path looks perfectly valid in: Source\Examples\WPF\ExampleBrowser\ExampleBrowser.csproj

Pepita related entry:
<UsingTask TaskName="PepitaGet.RestorePackagesTask" AssemblyFile="$(ProjectDir)........\Tools\Pepita\PepitaGet.dll" />

I'm using Visual Studio 2012.

Anyone know how to fix this?

After downloading the source I was trying to build the project by building the WPF Example browser specifically. That caused the error. If I instead open the solution and hit ctrl + shift + b it seems to build fine.

I am trying to use OxyPlot for real-time data plotting, but so far I've wasted a couple of hours without result. When I create a plot in XAML and add a LineSeries with ItemsSource binding, nothing happens when the binding source is updated (PropertyChanged eventhandlers and stuff are set-up correctly). Even calling RefreshPlot(true), which even seems to be unavailable in newer releases (240 has it, 261 does not), does not help.
The only time I actually see my data plotted is when I go zooming around the plot, the data is then updated at every zoom action (middle mouse drag).

To rule out compatibility errors, I created a small testing project.
MainWindow.xaml:

<Window x:Class="OxyPlotTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:oxy="http://oxyplot.codeplex.com"
        Title="MainWindow" Height="350" Width="525"
        MouseDown="Window_MouseDown">
    <Grid>
        <oxy:Plot Name="Plot" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
            <oxy:Plot.Axes>
                <oxy:LinearAxis Position="Bottom" Minimum="0" Maximum="10"/>
                <oxy:LinearAxis Position="Left" Minimum="-50" Maximum="50"/>
            </oxy:Plot.Axes>
            <oxy:Plot.Series>
                <oxy:LineSeries ItemsSource="{Binding PlotData}"/>
            </oxy:Plot.Series>
        </oxy:Plot>
    </Grid>
</Window>

MainWindow.xaml.cs

public partial class MainWindow : Window, INotifyPropertyChanged
    {
        public MainWindow()
        {
            InitializeComponent();
            this.DataContext = this;
            PlotData = new ObservableCollection<DataPoint>();
        }
        private ObservableCollection<DataPoint> _plotData = new ObservableCollection<DataPoint>();

        public ObservableCollection<DataPoint> PlotData
        {
            get { return _plotData; }
            set { _plotData = value; OnPropertyChanged("PlotData"); }
        }
        
        int x = 0;

        private void Window_MouseDown(object sender, MouseButtonEventArgs e)
        {
//create random datapoint on mouseclick
            Random r = new Random();
            int y = r.Next(-50, 50);
            PlotData.Add(new DataPoint(x,y));
            x++;
        }

        #region binding stuff
        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string name)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(name));
            }
        }
        #endregion
    }

The above code (with version 261) also does not work, a graph is only drawn when zooming. Not automatically.

I hope someone can help me, the problem is absolutely driving me mad, partly because I have seen this working in a fellow student's project.

1. OxyPlot is handling most mouse button events by default. Set a breakpoint in the event handler you created and you will see it is not being called. Try to press "shift+ctrl" and the left mouse button. This combination is not handled by OxyPlot and your event handler should be called. I think you have at least two alternatives to solve this:
   1. Use the PreviewMouseDown event instead.
   2. Unbind the left mouse button down gesture in the plot controller. This can be done by Plot.ActualController.Unbind(PlotCommands.SnapTrack); or Plot.ActualController.Unbind(OxyMouseButton.Left); (new extension method I just added)
2. OxyPlot is not observing collection changes, so you need to call Plot.InvalidatePlot() after you have added the point to the collection.

Thanks for your response!

The event-handler definitely was being called, when you click at the edge of the window, it will fire. Also, this is specific to my test set-up, in the actual project the binding source is updated by a DispatcherTimer.

I see copying the list, then adding the new datapoint to it and finally reassigning it to the binding source does update the graph like it should and so does Plot.InvalidatePlot(). However, it does not work in my original project with the DispatcherTimer, do you think the timer itself has something to do with the inability to update the plot (being on a another thread or something like that)?

Okay, I got this working in one specific way, the DispatcherTimer seems not to be the culprit. When I have this:

private List<DataPoint> _yPoints;

        public List<DataPoint> YPoints
        {
            get { return _yPoints; }
            set
            {
                _yPoints = value;
                RaisePropertyChanged("YPoints"); //OnPropertyChanged wrapper
            }
        }

I need to reassign YPoints completely with a new list, after adding a point as follows:

YPoints.Add(new DataPoint(x, y);
YPoints = new List<DataPoint>(YPoints);

If I don't perform the copy, no update, if I manually call RaisePropertyChanged("YPoints"), no update, if I call InvalidatePlot(true) on the plot, no update. Am I making sense here? Can you explain why it only works when I copy the data to a completely new list? It seems a rather inefficient way to handle data...

Hi,

I've started to look into this because I need it asap. It doesn't seem to be there yet, only some pieces coming from Silverlight port, I guess.
Essentially I would like to get the PlotModel.TrackerChanged event fired, which right now is sitting there unused.

What would be the approach to implement trackers with Xamarin? Is there somewhere a simplified version of Silverlight tracker already implemented?

Thx

great! the trackers in WPF and Silverlight are separate controls on top of the plot control. This makes it possible to show/hide the tracker without refreshing the plot control. The Windows forms project has a tracker implemented by a simple label, I would suggest a similar approach for the Xamarin ports. This should be implemented in the Plot controls (I think the iOS version currently does not have a custom plot control, but this should be fixed) and not by events.

It sounds doable. :)

Will try to do it for Monotouch for now, where Plot control is most likely a UIView.

Thx

I am very interested to see how this can be solved. Please see the updated iOS UIView implementation that I will check in soon.

I added this to
https://oxyplot.codeplex.com/workitem/10141

Please make a fork if you make some code that we can pull into the default branch!

I have pushed my changes on iOS to default. Note that the PlotView control does not handle touch events yet, I am awaiting issue #9625 to be pulled in first. The Show/Hide tracker functionality in the PlotView is unchanged by #9625.

Hello,
I'm using OxyPlot in an application to display a series of data that repeats, but with some noise in the data. The resulting chart looks similar to how an oscilloscope would look if you were triggering on a sine wave. When I plot just one cycle of data, and clear the points between each cycle, everything works great.

However, when I enable a "persistence" mode, where all old points remain in the series so that all past data is displayed in the chart, the updates get really slow after awhile. I assume this is because the number of points in the series becomes very large. Since the data is very nearly repeated for each cycle, but with some noise, the vast majority of "new" data points are identical to old data points that have already been added to the series. I'm thinking that if I could somehow check whether a particular X,Y data point already exists in the series, I could avoid adding a bunch of redundant data to the series, therefore keeping the number of points much smaller with the goal of avoiding the extremely slow updates.

So, with that background, my questions are:

• Is it possible to check whether a point exists in the series?
• How? Maybe something like:

    if (series.Points.contains(X,Y))
        // Discard the new X,Y point
    else
        series.Points.Add(new DataPoint(X, Y));

Thank you so much for any help or suggestions!

Dominic

You can use Enumerable.Any
In your code: series.Points.Any(p => p.X.Equals(X) && p.Y.Equals(Y))
See also 'Testing for equality' on http://msdn.microsoft.com/en-us/library/system.double.aspx

Thank you so much for the very fast response! That looks like it will do what I need. Now I will test to see if this strategy keeps my plot updates from bogging down...

Thank you again so much! I will report back with the results of my test.

Dominic

Thank you again for your help objo.

I would like to be able to get the list index for the point that matches. I found some references to a FindIndex() method of lists, but when I try to to do:

series.Points.FindIndex(p => p.X.Equals(X) && p.Y.Equals(Y))

I get an error saying that OxyPlot.IDataPoint does not contain a definition for FindIndex. I thought that since Any was supported, FindIndex would be supported also.

At this point I really just need to get the index for the first Points entry that matches the X value.

Do you have any suggestions? Thank you again so much for your help..

Dominic

Hello,

I met the same problem here in Winform. After pan or zoom, then if you change the series, the axes seems not to be refreshed.

Thanks.
Jo

I found the solution. Just call Reset() on the axis to reset ViewMaximum and ViewMinium after you change the series.

Thanks Zixys. Reset() works :D

What I want to do



What I have been able to do using line series chart



I switched to AreaChart but the result is not superb:



I guess the problem is because in area chart, I defined DataFieldY2 to be equal to zero, but I don't know how to do it another way. Here's my code:

public class DateValue
        {
            public DateTime Date { get; set; }
            public decimal Value { get; set; }
            public decimal Zero { get; set; }
        }

var points = new List<DateValue>();
points.Add(new DateValue{ Date = new DateTime(2010, 1, 1), Value = 5, Zero = 0 }); 
points.Add(new DateValue { Date = new DateTime(2010, 2, 1), Value = 45, Zero = 0 });
points.Add(new DateValue { Date = new DateTime(2010, 3, 1), Value = 16, Zero = 0 });

var _lineSeries = new AreaSeries()
                {
                    ItemsSource = points,  
                    Color = OxyColors.Blue,
                    Fill = OxyColor.FromRgb(214, 231, 242),
                    DataFieldX = "Date",
                    DataFieldY = "Value",
                    DataFieldX2 = "Date",
                    DataFieldY2 = "Zero",

            };
            model.Series.Add(_lineSeries);

Define both a LineSeries and an AreaSeries with transparent color for the lines of the AreaSeries. This way you won't have that zero line. Other solution could be setting the DataFieldY2 to a negative number and then limiting the AbsolutMinimum of the Y-axis. To get more similar look set transparency of AreaSeries, set a grid with solid lines, move the Y axis to the right and disable minor ticks. You should also touch the borders, they seems to be LightGray.ChangeAlpha(60) or so.

For the other graph is a bit more complicated but I think you can do it with CategoryAxis using bars.

Good luck

Define both a LineSeries and an AreaSeries with transparent color for the lines of the AreaSeries. This way you won't have that zero line

Your first solution looks simpler, can you please clarify what values do you set in your AreaSeries ? What about DataFieldX2, DateFieldY2 ?

Can you provide code example please.

var myArea = new AreaSeries();
var myLine = new LineSeries();

//Do the same that you do now

myLine.Points = myArea.Points;
myArea.Color = OxyColors.Transparent;

MyModel.Series.Add(myArea);
MyModel.Series.Add(myLine);

You need to add them in proper order to achieve that the LineSeries is on top of the AreaSeries

Hi,

I still got the same area chart which Y axis is stretched to zero:



What am I missing?

Here's my full code:

         var model = new PlotModel("AAAA", CurrentOrderSold.Identifier.Name);

            var dateTimeAxis = new DateTimeAxis(AxisPosition.Bottom, "Date")
            {
                IntervalType = DateTimeIntervalType.Months,
                StringFormat = "MMM yy",

            };

            model.Axes.Add(dateTimeAxis);
            

            var points = new List<DateValue>();
            foreach (var quote in Quotes.ToList())
                points.Add(new DateValue { Date = quote.TradingDate, Value = quote.Close, Zero = 0 });

            var linearSeries = new LineSeries("Price");

            var list = points.Select(source => new DataPoint(DateTimeAxis.ToDouble(source.Date), Convert.ToDouble(source.Value)))
                            .Cast<IDataPoint>().ToList();

            linearSeries.Points = list;

            var areaSeries = new AreaSeries()
            {
                ItemsSource = points,
                Color = OxyColors.Transparent,
                DataFieldX = "Date",
                DataFieldY = "Value",
                Fill = OxyColor.FromRgb(214, 231, 242),
                DataFieldX2 = "Date",
                DataFieldY2 = "Zero",


            };

            model.Series.Add(areaSeries);
            model.Series.Add(linearSeries);
            PlotModel = model;

  public class DateValue
    {
        public DateTime Date { get; set; }
        public decimal Value { get; set; }
        public decimal Zero { get; set; }
    }

```

If I understand you correctly you don't want the graph to start at 0 but at 14, as in your example. For that set the Minimum (or AbsolutMinimum) of your Y axis to 14. You may also adjust the padding to zero to avoid those white bands at each side.

omg thanks a lot. I just change Zero variable to be equal to the minimum value of my Quotes

The AreaSeries could also be modified so you could specify the color of the upper and lower line independently.
https://oxyplot.codeplex.com/workitem/10069

Hello.
I need to plot some numeric data as a function of audio frequency. The frequency axis (x axis) is in octave bands - which is base 2 log. Here's an example I found online of what I want to plot:

(reference: http://www.dpamicrophones.com/da/MikrofonUniversitet/Tech-Guide/Acoustics.aspx)
The picture is not very good quality, the frequency values are: 63, 125, 250, 500, 1k, 2k, 4k, 8k Hz.

I can't seem to be able to create such an axis. I've tried a few things without success:

1. Using log axis for frequency - but the values are calculated with a reference of 1. That means values count up as so: 1, 2, 4, 8, 16... etc. I need a way to set a custom reference (e.g. 1000 Hz) so I can start at 63 (or 62.5) and work my way up from there.
2. Using a category axis for frequency, so I can specify a custom string - but I need the labels to line up with the grid lines, not in between the grid lines (if that makes sense?)
3. Using a linear axis for frequency - but I see no way of replacing the numeric labels with custom strings.
   

Does anyone have any ideas? It seems like I need VS2012 (I have 2010) to open and compile the source, so I really am stuck. I think option 1. should be quite easy to implement?

You could just override the LogarithmicAxis.GetTickValues() without recompiling oxyplot as I did here.

A hacky, but nonetheless working, example (in VB I'm afraid):

Public Class MyLogAxis
    Inherits Axes.LogarithmicAxis

    Public Overrides Sub GetTickValues(ByRef majorLabelValues As IList(Of Double), ByRef majorTickValues As IList(Of Double), ByRef minorTickValues As IList(Of Double))
        majorTickValues = New List(Of Double)
 
        majorTickValues.Add(63)
        majorTickValues.Add(125)
        majorTickValues.Add(250)
        majorTickValues.Add(500)
        majorTickValues.Add(1000)
        majorTickValues.Add(2000)
        majorTickValues.Add(4000)
        majorTickValues.Add(8000)

        minorTickValues = majorTickValues
        majorLabelValues = majorTickValues

    End Sub
End Class

Ah, that's awesome. Thank you so much!

I would like to use OxyPlot in a WPF application, but appear to be encountering a performance issue. I have 8 plots in a scroll viewer, ~4 onscreen at a time. The plots are initialized and configured in code. They are updated in real-time with data (maybe 10 points per second each) up to a defined maximum amount. If I swap the type from WPF to WindowsForms using a hosted container, the performance doubles. Let me rephrase: WPF has 100% CPU usage and low UI response, WF has 50% CPU usage and good UI response.

Any idea why the difference in CPU usage/performance? Is there something I'm missing to get better WPF usage? I'm not using bindings; the simple code that works for WF is also used for WPF.

I've noticed the same thing. I am displaying different charts in WPF with OxyPlot, and the performance is not great (i.e. panning, zooming, and tracking). Some of the charts have as few as a dozen or two points and aren't updated dynamically. The WinForms example and the online Silverlight example work perfectly.

I think it's a problem with WPF itself.

It might be, but my test tries to use the objects using code rather than XAML/binding. The test application itself is WPF. The difference I'm noticing is in using the WPF version of OxyPlot vs the Windows Forms version hosted in the WPF application.

Can you profile your application to see if the time is spent in your application, the OxyPlot library or in the WPF core?
I have also noticed that other platforms are performing much better than WPF. It would be interesting to know if there is something that can be improved in the WPF implementation!

I have since gone ahead using a hosted WF OxyPlot. Seems I'll need a wrapper around it so that resizing will work properly.

I'll try putting together a test app once I have time and have a better idea how to use SharpDevelop's profiler; couldn't find a better one.

Below code is currently set to use OxyPlot.WindowsForms control in a WPF application. Change the XAML to use OxyPlot.WPF for comparison. I was unable to retrieve any insight using either SharpDevelop or SlimTune profilers. Perhaps someone else can make sense of the data.

XAML:

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:oxy="clr-namespace:OxyPlot.Wpf;assembly=OxyPlot.Wpf"
        xmlns:oxy2="clr-namespace:OxyPlot.WindowsForms;assembly=OxyPlot.WindowsForms"
        Title="MainWindow" Height="350" Width="525" Loaded="Window_Loaded" WindowState="Maximized">
  <!-- Comment/Uncomment the plot variant to use: WPF/WF -->
  <!--<oxy:Plot x:Name="MyPlot" />-->
  <WindowsFormsHost>
    <oxy2:Plot x:Name="MyPlot" />
  </WindowsFormsHost>
</Window>

Code behind:

using System;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication1 {
  /// <summary>
  /// Interaction logic for MainWindow.xaml
  /// </summary>
  public partial class MainWindow : Window {
    public MainWindow() {
      InitializeComponent();
      InitPlot();
      // initialize plot data points
      for(int i = 0; i < TOTAL_AXES; i++) {
        _SeriesIndex[i] = 0;
        sbyte _DataValue = 0;
        for(int j = 0; j < TOTAL_POINTS/2; j++) {
          _SeriesData[i].Add(new OxyPlot.DataPoint(_SeriesData[i].Count, _DataValue));
          _SeriesData[i].Add(new OxyPlot.DataPoint(_SeriesData[i].Count, -_DataValue));
          _DataValue++;
        }
      }
      // set up refresh timer for ~30fps
      _PlotRefresh.Interval = new TimeSpan(0, 0, 0, 0, 33);
      _PlotRefresh.Tick += new EventHandler(Timer_Tick);
    }

    private void InitPlot() {
      OxyPlot.Series.LineSeries srs = null;
      OxyPlot.Axes.LinearAxis axisBottom =
        new OxyPlot.Axes.LinearAxis(OxyPlot.Axes.AxisPosition.Bottom);
      OxyPlot.Axes.LinearAxis axisLeft = null;
      double wfpos = 1.0;

      MyPlot.Model = new OxyPlot.PlotModel();
      MyPlot.Model.Padding = new OxyPlot.OxyThickness(0);
      // single bottom axis
      axisBottom.MajorGridlineStyle = OxyPlot.LineStyle.Solid;
      axisBottom.MinorGridlineStyle = OxyPlot.LineStyle.Solid;
      axisBottom.MinimumPadding = 0;
      axisBottom.MaximumPadding = 0;
      MyPlot.Model.Axes.Add(axisBottom);

      for(int i = 0; i < TOTAL_AXES; i++) {
        // initialize each left axis
        axisLeft = new OxyPlot.Axes.LinearAxis();
        axisLeft.Position = OxyPlot.Axes.AxisPosition.Left;
        axisLeft.MajorGridlineStyle = OxyPlot.LineStyle.Solid;
        axisLeft.MinorGridlineStyle = OxyPlot.LineStyle.Solid;
        axisLeft.Minimum = -128;
        axisLeft.Maximum = 127;
        axisLeft.MinimumPadding = 0;
        axisLeft.MaximumPadding = 0;
        axisLeft.EndPosition = wfpos;
        wfpos -= ((1.0 / TOTAL_AXES) - 0.01);
        axisLeft.StartPosition = wfpos;
        wfpos -= 0.01;
        axisLeft.Key = "AxisKey" + i.ToString();
        MyPlot.Model.Axes.Add(axisLeft);
        // initialize each series for the axis
        _SeriesData.Add(new List<OxyPlot.IDataPoint>(TOTAL_POINTS));
        srs = new OxyPlot.Series.LineSeries();
        srs.CanTrackerInterpolatePoints = false;
        srs.StrokeThickness = 1;
        srs.Points = _SeriesData[i];
        srs.YAxisKey = axisLeft.Key;
        MyPlot.Model.Series.Add(srs);
      }
    }
    private void Window_Loaded(object sender, RoutedEventArgs e) {
      _PlotRefresh.Start();
    }
    private void Timer_Tick(object sender, EventArgs e) {
      // this is meant for use with dynamic data/series, but the effects
      // are similar using static data for testing
      MyPlot.RefreshPlot(true);
    }

    private const int TOTAL_AXES = 4;
    private const int TOTAL_POINTS = 512;
    private List<IList<OxyPlot.IDataPoint>> _SeriesData =
      new List<IList<OxyPlot.IDataPoint>>(TOTAL_AXES);
    private int[] _SeriesIndex = new int[TOTAL_AXES];
    private System.Windows.Threading.DispatcherTimer _PlotRefresh =
      new System.Windows.Threading.DispatcherTimer();
  }
}

Not sure how much help this is, but I have some results from the WPF Performance Suite (part of Windows SDK). It's not very detailed, but it indicates "Rendering Thread" uses 50% CPU time and "Layout" uses 20%. As far as I can tell, WPF/OxyPlot is using hardware acceleration. RenderingCapabilities.Tier returns 2, which is the highest value indicating support for hardware acceleration. The performance suite also indicates the entire OxyPlot control being frequently marked as "dirty" and requiring refreshing/rendering. This is probably expected behavior when issuing RefreshPlot(true).

(Formatting is lacking, just copy the table into notepad.)
"Top 20" results from SharpDevelop profiler:

Name                                                       Call Count   Time Spent     TS (self)      TS (per call)   TS (self/call)
------------------------------------------------------------------------------------------------------------------------------------
WpfApplication1.App.Main                                       1      19487.779297ms   26.708881ms   19487.779297ms   26.708881ms                                     
OxyPlot.Wpf.Plot.ArrangeOverride                              22       6385.794584ms    0.526685ms     290.263390ms    0.023940ms                                     
OxyPlot.Wpf.Plot.UpdateModelAndVisuals                        21       6327.732324ms    3.068244ms     301.320587ms    0.146107ms                                     
OxyPlot.Wpf.Plot.UpdateVisuals                                21       5852.759366ms    3.663617ms     278.702827ms    0.174458ms                                     
OxyPlot.PlotModel.Render                                      21       4932.378369ms   14.397502ms     234.875160ms    0.685595ms                                     
WpfApplication1.MainWindow..ctor                               1       3128.988608ms   60.921899ms    3128.988608ms   60.921899ms                                     
OxyPlot.PlotModel.RenderAxes                                  42       2628.290695ms    0.843887ms      62.578350ms    0.020093ms                                     
OxyPlot.Axes.Axis.Render                                     210       2627.099862ms    1.284219ms      12.509999ms    0.006115ms                                     
OxyPlot.HorizontalAndVerticalAxisRenderer.Render             210       2625.815643ms   13.369001ms      12.503884ms    0.063662ms                                     
WpfApplication1.MainWindow.InitializeComponent                 1       2268.427159ms    1.322134ms    2268.427159ms    1.322134ms                                     
OxyPlot.HorizontalAndVerticalAxisRenderer.RenderMajorItems   105       1827.486131ms    4.793490ms      17.404630ms    0.045652ms                                     
OxyPlot.MathRenderingExtensions.DrawMathText                 798       1570.425264ms    1.443802ms       1.967951ms    0.001809ms                                     
OxyPlot.MathRenderingExtensions.DrawMathText                 798       1568.981462ms    4.374377ms       1.966142ms    0.005482ms                                     
OxyPlot.Wpf.ShapesRenderContext.DrawText                     798       1561.215147ms   11.262844ms       1.956410ms    0.014114ms                                     
OxyPlot.PlotModel.AdjustPlotMargins                           21       1155.307446ms   14.229514ms      55.014640ms    0.677596ms                                     
OxyPlot.PlotModel.MaxSizeOfPositionTier                       42       1120.887111ms    1.372298ms      26.687788ms    0.032674ms                                     
OxyPlot.Axes.Axis.Measure                                    105       1119.405653ms    4.064151ms      10.661006ms    0.038706ms                                     
OxyPlot.PlotModel.RenderSeries                                21       1091.402684ms    2.620846ms      51.971556ms    0.124802ms                                     
WpfApplication1.App..ctor                                      1       1088.683889ms  161.166694ms    1088.683889ms  161.166694ms                                     
OxyPlot.Series.LineSeries.Render                              84       1087.583511ms   76.632450ms      12.947423ms    0.912291ms                                     

I also have the SharpDevelop profile project file if needed (~20MB).

__First and the most important:__GREAT library. Thank you.

Does OxyPlot support addition/subtraction/division/multiplication of line graphs? Say I have two series that have different X spacing, I can't add directly one to another because the X values do not exist. Please check this picture (done in Excel)



Note that the line between each pair of points only exists while plotting. Is there a way of access that data for directly add all lines in the plot?

I've written a method for creating new points when they are needed but it's difficult to implement and not very good for performance. It would be great if someone guide me a little bit in the right direction. Thank you!

Stacking is supported for BarSeries (that use category axes) but not for LineSeries and AreaSeries.
The easiest solution now would be to do the interpolation/extrapolation inside your application, this would also be better for performance (the LineSeries will need to interpolate every time it updates the data)

See also the fork stackedarealineseries:
https://oxyplot.codeplex.com/SourceControl/network/forks/benjaminrupp/StackedAreaLineSeries

Thanks for the answer objo!

Here is the code for implementing Line addition in OxyPlot:
It checks if the line is null, and only plots where both lines exist.
I hope this may be useful for someone. I've received so much from the Internet and it's time to give something in return =)
Sorry but the variables/classes names are in Spanish (I don't have time right now to change them to English)

You need to call SumarNoEquiespaciado method that accepts two Lists of DataPoint.

class Operaciones
    {
        #region SumarNoEquiespaciado
        public static  IList<DataPoint> SumarNoEquiespaciado(IList<DataPoint> S1, IList<DataPoint> S2)
        {
            IList<DataPoint> Suma = new List<DataPoint>();
            IList<DataPoint> NS1 = new List<DataPoint>();
            IList<DataPoint> NS2 = new List<DataPoint>();

            

            if (S1.Any() && S2.Any())
            {
                
                NS1 = ObtenerPuntosIntermedios(S1, S2);
                NS2 = ObtenerPuntosIntermedios(S2, NS1);
                
                Suma = SumarEquiespaciado(NS1, NS2);
                
            }

            return Suma;
        }
        #endregion

        #region SumarEquiespaciado

        public static  IList<DataPoint> SumarEquiespaciado(IList<DataPoint> S1, IList<DataPoint> S2)
        {

            List<DataPoint> Suma = new List<DataPoint>();
            int PuntosEnS1 = S1.Count;
            int PuntosEnS2 = S2.Count;

            if (S1.Any() && S2.Any())
            {

                if (S1[0].X >= S2[0].X)
                {

                    if (S1[PuntosEnS1 - 1].X >= S2[PuntosEnS2 - 1].X)
                    {

                        Suma = SumarEquiespaciadoCaso2(S1, S2).ToList();
                    }

                    if (S1[PuntosEnS1 - 1].X < S2[PuntosEnS2 - 1].X)
                    {

                        Suma = SumarEquiespaciadoCaso1(S1, S2).ToList();
                    }
                }
                else
                {
                    if (S2[PuntosEnS2 - 1].X >= S1[PuntosEnS1 - 1].X)
                    {
                        Suma = SumarEquiespaciadoCaso2(S2, S1).ToList();
                    }

                    if (S2[PuntosEnS2 - 1].X < S1[PuntosEnS1 - 1].X)
                    {
                        Suma = SumarEquiespaciadoCaso1(S2, S1).ToList();
                    }

                }
            }


            return Suma;


        }

        #region Metodos De Ayuda para SumarEquiespaciado

        private static IList<DataPoint> SumarEquiespaciadoCaso2(IList<DataPoint> S1, IList<DataPoint> S2)
        {
            IList<DataPoint> Suma = new List<DataPoint>();
            int PuntosEnS1 = S1.Count;
            int PuntosEnS2 = S2.Count;

            int i = 0;
            int j = S2.TakeWhile(p => p.X < S1[0].X).Count();

            while (j < PuntosEnS2)
            {

                DataPoint punto = new DataPoint(S1[i].X, S1[i].Y + S2[j].Y);
                Suma.Add(punto);
                i++;
                j++;

            }

            return Suma;
        }

        private static IList<DataPoint> SumarEquiespaciadoCaso1(IList<DataPoint> S1, IList<DataPoint> S2)
        {
            IList<DataPoint> Suma = new List<DataPoint>();
            int PuntosEnS1 = S1.Count;
            int PuntosEnS2 = S2.Count;

            int i = 0;
            int j = S2.TakeWhile(p => p.X < S1[0].X).Count();

            while (i < PuntosEnS1)
            {

                DataPoint punto = new DataPoint(S1[i].X, S1[i].Y + S2[j].Y);
                Suma.Add(punto);
                i++;
                j++;

            }

            return Suma;
        }


        #endregion




        #endregion

        #region ObtenerPuntosIntermedios


        private static IList<DataPoint> ObtenerPuntosIntermedios(IList<DataPoint> S1, IList<DataPoint> S2)
        {
            IList<DataPoint> NS1 = new List<DataPoint>();

            int i = 0;
            int j = S2.TakeWhile(p => p.X < S1[0].X).Count();


            int PuntosEnS1 = S1.Count;
            int PuntosEnS2 = S2.Count;

            DataPoint nuevoPunto = new DataPoint();


            while (i < PuntosEnS1)
            {
                if (j < PuntosEnS2)
                {
                    if (S1[i].X < S2[j].X)
                    {
                        nuevoPunto = S1[i];
                        NS1.Add(nuevoPunto);
                        i++;
                    }

                    else if (S1[i].X == S2[j].X)
                    {

                        nuevoPunto = S1[i];
                        NS1.Add(nuevoPunto);
                        i++;
                        j++;
                    }

                    else if (S1[i].X > S2[j].X)
                    {
                        nuevoPunto.X = S2[j].X;
                        nuevoPunto.Y = S1[i - 1].Y + (S2[j].X - S1[i - 1].X) * (S1[i].Y - S1[i - 1].Y) / (S1[i].X - S1[i - 1].X);
                        NS1.Add(nuevoPunto);
                        j++;

                    }

                }

                if ((j == PuntosEnS2) && (S1[PuntosEnS1 - 1].X != S2[PuntosEnS2 - 1].X))
                {
                    nuevoPunto = S1[i];
                    NS1.Add(nuevoPunto);
                    i++;
                }


            }

           
            return NS1;

        }

        #endregion
    }