How to plot data imported from a csv? - excel

Question

I am trying to import CSV output data from a simulation into an Excel sheet to plot the data in a regular XY scatter chart.
I managed everything except the end result. The data is imported from csv to Excel, points are replaced by commas as a decimal separator.
It is plotting a straight horizontal line at 0 y-coordinates.
I noticed that the values in Excel are stored as texts, although I specified the format for numerical contents of csv as numbers like following:
DataSheet.Cells(Row, col).NumberFormat = "0.E+00"
When I test Isnumeric(cell.value), it turns out positive.
My complete code:
CsvFile = Application.GetOpenFilename()
Set DataSheet = Worksheets("CSV_Plot")
nrow = 10 'data starts at 10th row
Open CsvFile For Input As #1
Do Until EOF(1)
Line Input #1, CsvLine
CsvItem = Split(CsvLine, ",")
If Not CsvItem(0) <> "" Then GoTo 10 'ignores first line
ncol = UBound(CsvItem) 'ncol = number of data columns
If IsNumeric(CsvItem(0)) Then
For i = 0 To ncol
CsvItem(i) = Replace(CsvItem(i), ".", ",") 'replace point with comma in 'numerical values
Next i
End If
Add1 = DataSheet.Cells(nrow, LBound(CsvItem) + 1).Address
Add2 = DataSheet.Cells(nrow, ncol + 1).Address
DataSheet.Range(Add1 & ":" & Add2) = CsvItem
nrow = nrow + 1
10:
Loop
nrowlast = nrow
Close #1
For Row = 11 To nrowlast
For col = 1 To ncol
DataSheet.Cells(Row, col).Select
DataSheet.Cells(Row, col).NumberFormat = "0.E+00"
Next col
Next Row
Set ChtObj = DataSheet.ChartObjects.Add(50, 50, 500, 300)
Set Cht = ChtObj.Chart
With Cht
.ChartType = xlXYScatterLines
.SeriesCollection.NewSeries
.SeriesCollection(1).XValues = DataSheet.Range("A11:A35")
.SeriesCollection(1).Values = DataSheet.Range("N11:N35")
End With

Answer 1

EDIT: I think your problem is this line: CsvItem = Split(CsvLine, ","). The return type of Split should be a String. I don't know what your data looks like but you could try casting it as Double if decimal places are relevant. Otherwise cast it as Long: CsvItem = CLng(Split(CsvLine, ",")).
Original answer:
I updated the relevant parts of your code:
For Row = 11 To nrowlast
For col = 1 To ncol
DataSheet.Cells(Row, col).NumberFormat = "0.E+00"
Next col
Next Row
I took out the .Select statement as it is unnecessary and might lead to errors. Here is the main part part:
Dim ChtObj As Object
Set ChtObj = DataSheet.Shapes.AddChart2(, xlXYScatterLines, 50, 50, 500, 300)
With ChtObj.Chart
.SeriesCollection.NewSeries
.SeriesCollection(1).XValues = DataSheet.Range("A11:A35")
.SeriesCollection(1).Values = DataSheet.Range("N11:N35")
End With
This should work as intended.

Answer 2

After some effort, i was able to locate the source of problem: I had defined CsvItem() as string and that's why when I execute the statement DataSheet.Range(Add1 & ":" & Add2) = CsvItem, the values in excel were always text irrespective of the format.
The solution to this was to define a variable to hold numerical values of CsvItem and assign this value to excel cells:
Dim CsvVal() As Double
CsvVal(i) = CDbl(CsvItem(i))
DataSheet.Range(Add1 & ":" & Add2).Value = CsvVal
this eventually produced the result I wanted.