Microsoft chart bar chart diagram has spaces

Question

I use the .Net 4.0 chart library to create a multi-series column bar chart. My goal is a histogram showing the total number of actions (finalization of reports) per day in several series (teachers). Often there is no data (on the same day a certain teacher has no activity).

I get spaces in bars when there is no data in the series:

My code is:

public ActionResult CompletionHistogram(int sid, int width, int height) { Site site = SiteRepository.Get(sid); if (site == null) return new HttpNotFoundResult(); Chart chart = new Chart(); chart.Height = height; chart.Width = width; ChartArea area = chart.ChartAreas.Add("Default"); // Treat each teacher as a series foreach (Teacher t in site.Teachers) { Series series = chart.Series.Add(t.FullName); series.ChartType = SeriesChartType.StackedColumn; series.Name = t.FullName; // Group completions by day (filter out incomplete reports and null timestamps) var groups = t.StudentReports .Where<StudentReport>(rep => rep.IsComplete && rep.FirstSaveTimestamp.HasValue) .GroupBy<StudentReport, DateTime>(rep => rep.FirstSaveTimestamp.Value.Date); bool hasPoints = false; foreach (var g in groups) { series.Points.AddXY(g.Key, g.Count()); hasPoints = true; } series.IsValueShownAsLabel = true; series.ToolTip = "#VALX"; if (hasPoints) chart.DataManipulator.InsertEmptyPoints(1, IntervalType.Days, series); } area.AxisX.LabelStyle.Format = "ddd M/d"; return new ChartResult(chart); } 

How to delete

Answer 1

I have a way to make this work.
Sorry for the long answer, but I found a way by which you try to implement this answer will affect if it works or not.

You need to set zero manually when you add points. Note. I could not do this job by adding zero points after the fact.

See the following example and screenshots: chart1.Series.Clear (); chart1.Series.Add (new series ()); chart1.Series.Add (new series ()); chart1.Series.Add (new series ()); chart1.Series.Add (new series ());

 foreach (Series s in chart1.Series) { s.ChartType = SeriesChartType.StackedColumn; } //chart1.Series[0].Points.Add(new DataPoint(0, 0)); chart1.Series[0].Points.Add(new DataPoint(1, 3)); chart1.Series[0].Points.Add(new DataPoint(2, 3)); chart1.Series[0].Points.Add(new DataPoint(3, 3)); chart1.Series[1].Points.Add(new DataPoint(0, 3)); //chart1.Series[1].Points.Add(new DataPoint(1, 0)); chart1.Series[1].Points.Add(new DataPoint(2, 3)); chart1.Series[1].Points.Add(new DataPoint(3, 3)); chart1.Series[2].Points.Add(new DataPoint(0, 3)); chart1.Series[2].Points.Add(new DataPoint(1, 3)); //chart1.Series[2].Points.Add(new DataPoint(2, 0)); chart1.Series[2].Points.Add(new DataPoint(3, 3)); chart1.Series[3].Points.Add(new DataPoint(0, 3)); chart1.Series[3].Points.Add(new DataPoint(1, 3)); chart1.Series[3].Points.Add(new DataPoint(2, 3)); //chart1.Series[3].Points.Add(new DataPoint(3, 0)); chart1.SaveImage("C:\\Before.png", ChartImageFormat.Png); 

Image of "before.png":

Now delete the comments for the series without any data points for the given x value:

(Note: I didn’t find this to work if you added points at a given x-value for the values ​​where you do y = 0 at the end - aka right before saving the image. The order of the points in the series seems to matter for StackedColumn, I have never worked with this type, except to explore how to answer this question, so that they can be well known to users of this type)

 chart1.Series.Clear(); chart1.Series.Add(new Series()); chart1.Series.Add(new Series()); chart1.Series.Add(new Series()); chart1.Series.Add(new Series()); foreach (Series s in chart1.Series) { s.ChartType = SeriesChartType.StackedColumn; } chart1.Series[0].Points.Add(new DataPoint(0, 0)); chart1.Series[0].Points.Add(new DataPoint(1, 3)); chart1.Series[0].Points.Add(new DataPoint(2, 3)); chart1.Series[0].Points.Add(new DataPoint(3, 3)); chart1.Series[1].Points.Add(new DataPoint(0, 3)); chart1.Series[1].Points.Add(new DataPoint(1, 0)); chart1.Series[1].Points.Add(new DataPoint(2, 3)); chart1.Series[1].Points.Add(new DataPoint(3, 3)); chart1.Series[2].Points.Add(new DataPoint(0, 3)); chart1.Series[2].Points.Add(new DataPoint(1, 3)); chart1.Series[2].Points.Add(new DataPoint(2, 0)); chart1.Series[2].Points.Add(new DataPoint(3, 3)); chart1.Series[3].Points.Add(new DataPoint(0, 3)); chart1.Series[3].Points.Add(new DataPoint(1, 3)); chart1.Series[3].Points.Add(new DataPoint(2, 3)); chart1.Series[3].Points.Add(new DataPoint(3, 0)); // If you add the empty points here, it does not seem to work. // Empty points are as follows, and are already added above in the 'after' example. // chart1.Series[0].Points.Add(new DataPoint(0, 0)); // chart1.Series[1].Points.Add(new DataPoint(1, 0)); // chart1.Series[2].Points.Add(new DataPoint(2, 0)); // chart1.Series[3].Points.Add(new DataPoint(3, 0)); chart1.SaveImage("C:\\After.png", ChartImageFormat.Png); 

Image of "after.png":

So, given that after the fact you cannot add zero points (although you can insert them?), You will need to change your code to something like this:

 var allPossibleGroups = t.StudentReports; var groups = t.StudentReports .Where<StudentReport>(rep => rep.IsComplete && rep.FirstSaveTimestamp.HasValue) .GroupBy<StudentReport, DateTime>(rep => rep.FirstSaveTimestamp.Value.Date); bool hasPoints = false; foreach (var g in allPossibleGroups) { if(groups.ContainsKey(g)) { series.Points.AddXY(g.Key, g.Count()); hasPoints = true; } else { series.Points.AddXY(g.Key, 0); } } 

Sorry for the long blocks of code, but this example was necessary to demonstrate how to make it work without falling into the trap of adding empty dots (where y = 0) at the end, as this will not work.

Let me know if you need more help.

Answer 2

Go to the same problem yourself and want to share the right solution:

Use DataManipulator to insert missing values ​​(x, y):

 foreach (Series s in chart.Series) { chart.DataManipulator.Sort(PointSortOrder.Ascending, "X", s); chart.DataManipulator.InsertEmptyPoints(1, IntervalType.Number, s); } 

Answer 3

The loop loop does not work for me for some reason, but the following solution works like a charm:

 Chart1.DataManipulator.InsertEmptyPoints(1, IntervalType.Number, "Series1, Series2, Series3, Series4")