Powershell to create line chart from EXCEL - excel

Question

My powershell script inputs data into EXCEL worksheet
and I am trying to create a line chart that will resemble
However, this is the code I have so far:
$xlConditionValues=[Microsoft.Office.Interop.Excel.XLConditionValueTypes]
$xlTheme=[Microsoft.Office.Interop.Excel.XLThemeColor]
$xlChart=[Microsoft.Office.Interop.Excel.XLChartType]
$xlIconSet=[Microsoft.Office.Interop.Excel.XLIconSet]
$xlDirection=[Microsoft.Office.Interop.Excel.XLDirection]
...
$chart=$ws.Shapes.AddChart().Chart
$chart.chartType=$xlChart::xlBarClustered
$start=$ws.range("A1")
$Y=$ws.Range($start,$start.End($xlDirection::xlDown))
$start=$ws.range("B2")
$X=$ws.Range($start,$start.End($xlDirection::xlDown))
$chartdata=$ws.Range("A$($Y.item(1).Row):A$($Y.item($Y.count).Row),B$($X.item(1).Row):B$($X.item($X.count).Row)")
$chart.SetSourceData($chartdata)
#add labels
$chart.seriesCollection(1).Select() | Out-Null
$chart.SeriesCollection(1).ApplyDataLabels() | out-Null
#modify the chart title
$chart.ChartTitle.Text = "Number of Computer"
$ws.shapes.item("Chart 1").top=40
And this is the graph it generates
How do I even begin to fix this? Any helpful tutorials?

Answer 1

Degustaf is 100% correct, his is the correct answer, but you have a lot of extra stuff in there that isn't needed. I can replicate your desired outcome including populating the spreadsheet with your test data, and do it in fewer lines than what you have. Here, check this out, you may come away with a few pointers for your future endeavors.
#Test Data
$Data=("8/15/2014",3091),("8/14/2014",240),("8/13/2014",519),("8/12/2014",622),("8/11/2014",2132),("8/10/2014",1255),("8/9/2014",3240)|ForEach{[PSCustomObject][Ordered]#{'Date_to_Display'=$_[0];'Number_of_Computers'=$_[1]}}
$xlConditionValues=[Microsoft.Office.Interop.Excel.XLConditionValueTypes]
$xlTheme=[Microsoft.Office.Interop.Excel.XLThemeColor]
$xlChart=[Microsoft.Office.Interop.Excel.XLChartType]
$xlIconSet=[Microsoft.Office.Interop.Excel.XLIconSet]
$xlDirection=[Microsoft.Office.Interop.Excel.XLDirection]
$xl = new-object -ComObject Excel.Application
$wb = $xl.workbooks.add()
$ws = $wb.activesheet
$xl.Visible = $true
#Populate test data onto worksheet
$Data |ConvertTo-CSV -NoTypeInformation -Delimiter "`t"| c:\windows\system32\clip.exe
$ws.Range("A1").Select | Out-Null
$ws.paste()
$ws.UsedRange.Columns.item(1).numberformat = "dddd, mmm dd, yyyy"
$ws.UsedRange.Columns.AutoFit() |Out-Null
#Create Chart
$chart=$ws.Shapes.AddChart().Chart
$chart.chartType=$xlChart::xlLine
#modify the chart title
$chart.ChartTitle.Text = "Number of Computers"
$ws.shapes.item("Chart 1").top=40
If you work with Powershell and Excel much you'll probably find the line up there $Data|ConvertTo-CSV... extremely useful.

Answer 2

Based on my experience with VBA, it appears that the first thing to try is changing your chart type. You have $chart.chartType=$xlChart::xlBarClustered. Based on the similar VBA commands, I would try changing this to $chart.chartType=$xlChart::xlLine. That should make a big difference, and let you see what else needs to be tweaked.

Answer 3

Fancy stuff to avoid seeing unnecessary red lines (Exception setting "ChartType": "Unspecified error) all over:
$chart.chartType = 4
Detailed list of chart types and more information available here: http://learn-powershell.net/2012/12/24/powershell-and-excel-adding-a-chart-and-header-filter-to-a-report/