How can I use Grapher automation to set the weights for my weighted average fit curve?

This article contains a sample script for setting the weights for a weighted average fit curve. Note that there are two sections of the script.  The first section contains direct commands that can be used to adjust the weight parameters in Grapher 14 and newer versions. The second section contains and example of how to set the weights in Grapher 13 down to Grapher 5.

To run this script:

1. Copy the script below.
2. Open Grapher and turn on the Script Manager by clicking View | Display | Script Manager.
3. Press Ctrl+A to select all of the existing lines in the Script Manager and then press DELETE.
4. Press Ctrl+V to paste it into the Script Manager.
5. Click the green arrow Start/Resume icon in the Script Manager.

Sub Main
  Dim GrapherApp As Object
  Set GrapherApp = CreateObject("Grapher.Application")
  GrapherApp.Visible = True

  'Add plot window
  Set Plot = GrapherApp.Documents.Add(grfPlotDoc)
  'Add graph
  Set LineGraph = Plot.Shapes.AddLinePlotGraph(GrapherApp.Path+"\samples\sample3.dat")
  'Set LinePlot to the line plot object
  Set LinePlot = LineGraph.Plots.Item(1)
  'Add fit
  LinePlot.AddFit(grfWeightedAvgFit)
  'Set LineFit to the fit curve object
  Set LineFit = LinePlot.Fits.Item(1)


 '---- Grapher 14 and newer support using the commands below. ----
 'Set the LineFit options -- for weighted fit, this is the window width 
  LineFit.Option = 5
  
  'Set the LineFit options -- for weighted fit, this is the window width
  LineFit.Option = 3
  LineFit.SetWeight(1,1)  'Sets the order 1 weight to 1
  LineFit.SetWeight(2,1)  'Sets the order 2 weight to 1
  LineFit.SetWeight(3,2)  'Sets the order 3 weight to 2
  LineFit.SetWeight(4,2)  'Sets the order 4 weight to 2
  LineFit.SetWeight(5,1)  'Sets the order 5 weight to 1

 '---- Grapher 13 and older versions use SendKeys to set the weight parameters. ----
 'Set the LineFit options -- for weighted fit, this is the window width 
  LineFit.Option = 3
  'Select the fit curve
  LineFit.selected = True

  'Linefit weighted fits -- how to set the weights in G5 through PI
   AppActivate "Grapher"
   SendKeys "%{Enter}"       	'activates PI
   SendKeys "{Left}"           	'insure Plot section Is closed
   SendKeys "{Right}"          	'expand Plot section
   SendKeys "{Down}"         	'move selection down To Weights Dialog control
   SendKeys "{Down}"
   SendKeys "{Down}"
   SendKeys "{Enter}"         	'bring up Weights Dialog

  'The Weights dialog is open.  Go to first entry, tab to Set Weight button and press Enter
   SendKeys "{Down}"
   SendKeys "{Tab}"
   SendKeys "{Enter}"

  'Set the weight for the first item using SendKeys
   SendKeys "5"
   SendKeys "{Enter}"

  'Go to the second entry, tab to Set Weight button and press Enter
   SendKeys"+{Tab}"	'+ indicates Shift is pressed
   SendKeys "{Down}"
   SendKeys"{Tab}"
   SendKeys "{Enter}"

  'Set the weight for the second item using SendKeys
   SendKeys "2"
   SendKeys "{Enter}"

  'Go to the third entry, tab to Set Weight button and press Enter
   SendKeys"+{Tab}"	'+ indicates Shift is pressed
   SendKeys "{Down}"
   SendKeys"{Tab}"
   SendKeys "{Enter}"

  'Set the weight for the third item using SendKeys
   SendKeys "3"
   SendKeys "{Enter}"

 'Close dialog
   SendKeys"{Tab}"
   SendKeys"{Enter}"

End Sub

Updated March 6, 2019