Plot and add best fit trend

[cmauras]

I recorded this Macro to plot cells that I highlight, open as a new sheet and add an exponential trend displaying the equation and R^2 value. There are two problems: the macro does not plot the highlighted cells, rather it plots the entire columns; and when it is time to open the chart as a new sheet it stops because the sheet name is not changing, and cannot create two sheets with the same name.

I would also like to add a few lines so that it goes through different trends and compares the R^2 values, therefore selecting the best fit. Any help will be greatly appreciated.

Charts.Add
ActiveChart.ChartType = xlXYScatter
ActiveChart.SetSourceData Source:=Sheets("4-K0 2002-01-28 16-19-32").Range("G" & ":H"), PlotBy:=xlColumns
ActiveChart.Location Where:=xlLocationAsObject, Name:= _
"4-K0 2002-01-28 16-19-32"
With ActiveChart
.HasTitle = False
.Axes(xlCategory, xlPrimary).HasTitle = True
.Axes(xlCategory, xlPrimary).AxisTitle.Characters.Text = "time"
.Axes(xlValue, xlPrimary).HasTitle = True
.Axes(xlValue, xlPrimary).AxisTitle.Characters.Text = "mg/m^3"
End With
With ActiveChart.Axes(xlCategory)
.HasMajorGridlines = False
.HasMinorGridlines = False
End With
With ActiveChart.Axes(xlValue)
.HasMajorGridlines = False
.HasMinorGridlines = False
End With
ActiveChart.HasLegend = False
ActiveChart.SeriesCollection(1).Trendlines.Add(Type:=xlExponential, Forward _
:=0, Backward:=0, DisplayEquation:=True, DisplayRSquared:=True).Select
ActiveChart.SeriesCollection(1).Trendlines(1).DataLabel.Select
Selection.Left = 205
Selection.Top = 52
End Sub

[Damon Ostrander]

Hi Cmauras,

First of all, to get the chart to use the selected rather than hard-wired range, change

Sheets("4-K0 2002-01-28 16-19-32").Range("G" & ":H")

to

Selection

In order to get a unique name each time, you must come up with a naming strategy. For example, if you want the chart name to contain the current date and time (as in your example, but updated to the current time), you could do this

..., Name:= _
"4-K0 " & Format(Now(),"yyyy-mm-dd hh-mm-ss")

which encodes the current time into the name in the same format you are using now.

Sorry, but I don't have time right now to answer your R^2 question.

[cmauras]

Thank you for your reply. I tried using Selection, but it did not seem to work. Is there anything else to type on this command?

[Damon Ostrander]

Hi again cmauras,

Yes, I see why the Selection won't work. When you create the chart without assigning it to an object variable, it becomes the selected object. To get around this simply save the selection before creating the chart:

Dim SelData As Range

Set SelData = Selection

Charts.Add
ActiveChart.ChartType = xlXYScatter
ActiveChart.SetSourceData Source:=SelData, PlotBy:=xlColumns

etc.

[cmauras]

Thank you Damon. This worked.