Visual Basic Spline Chart

smal 20

Hello. I'm creating in visual basic an application that displays the values taken from different csv files. After having selected the files, the graph appears as in the figure.

Immagine 2023-01-30 154227

What should I set so that vertical lines do not appear?

Accepted answer

Michael Taylor 48,281

Please provide us more context. You are asking how to disable lines but you haven't told us anything about your app beyond it being VB. What type of app is it (web form, winforms, XAML), what control are you using to get the graph, what vertical lines specifically (column headers)?

smal 20

My app is in winforms. I use a Chart control. And this is the code I wrote:

 Dim openFileDialog1 As New OpenFileDialog With {
            .Filter = "CSV files (*.csv)|*.csv",
            .FilterIndex = 1,
            .Multiselect = True,
            .Title = "Select only CSV files"
        }

        If openFileDialog1.ShowDialog() = DialogResult.OK Then
            Chart1.Visible = True
            If Chart1.Series.Count > 0 Then
                Chart1.Series.Clear()
            End If

            Dim fileCounter As Integer = 0

            For Each file As String In openFileDialog1.FileNames
                fileCounter += 1
                Dim lineCounter As Integer = 0
                Dim sr As New StreamReader(file)
                Dim currentLine As String

                While sr.Peek() >= 0
                    currentLine = sr.ReadLine()
                    lineCounter += 1

                    If lineCounter = 1 Then
                        Dim series As New Series With {
                            .Name = Path.GetFileNameWithoutExtension(file),
                            .ChartType = SeriesChartType.Spline
                        }
                        Chart1.Series.Add(series)
                    Else
                        Dim values() As String = currentLine.Split(",")
                        Dim timers As String = values(0)
                        Dim speed As Double = Double.Parse(values(1))
                        Chart1.Series(fileCounter - 1).Points.AddXY(timers, speed)
                    End If
                End While
                sr.Close()
            Next

            Chart1.Series(0).ChartType = SeriesChartType.Spline
        End If

The vertical lines I mean are the blue ones.

Michael Taylor 48,281 Reputation points

2023-01-30T16:22:29.3633333+00:00

So if I understand correctly you want to hide the vertical lines that delineate the time labels listed at the bottom of the chart.

In the designer edit the properties of the grid. Go to the ChartAreas and then edit the (probably only) chart area you have. Find the Axes property and edit it. On the X Axis property go to the GridTickMarks \ majorGrid property. Disable it and the vertical grid will go away.

2 additional answers

smal 20 Reputation points

2023-01-30T17:15:45.2033333+00:00

I've noticed that blue vertical lines are created when a value in the series is missing. How can I fix?
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Michael Taylor 48,281 Reputation points

2023-01-30T18:28:48.2566667+00:00

Can you show us in a screenshot what you're seeing? The only blue vertical lines in the original screenshot was the data. If you're seeing data when there isn't any then I believe the issue is that there is data. Of course you're using a spline so it'll interpolate the data points in order to fill in the curves. If there is missing data then it'll just connect the 2 points that do exist. If you don't want that behavior then a spline chart isn't the right chart option for you. You'd more likely want just the points.

smal 20 Reputation points

2023-01-30T18:48:00.6+00:00

here I highlight what I mean, to which values I refer

Michael Taylor 48,281 Reputation points

2023-01-30T19:25:06.0633333+00:00

That's how spline charts work. The chart divides the data up into intervals and then for each interval it draws a point for that value. Then it connects them using a curved line. If the value is 0 (or missing) then it should be showing that. In your case I wonder if you should be using a spline chart at all.

But irrelevant if you don't want these missing points then the correct approach is to fix your data before binding it to the chart. It is a data issue, not a UI one. What you could do is look for gaps (based upon your intervals) and then set/insert into the gap the value from the previous value. Or you could interpolate between the previous and next, whatever algorithm you want to use.
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smal 20 Reputation points

2023-01-30T20:01:18.67+00:00
The numbers in the series are decimal, but in the American style, i.e. floating point with . While in Italy we are in the habit of using the ,

I fixed it by changing the culture with the code:

Threading.Thread.CurrentThread.CurrentCulture = New CultureInfo("us-US") Threading.Thread.CurrentThread.CurrentCulture.NumberFormat.NumberDecimalSeparator = "."
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