Reputation: 60711
i have a histogram in Excel. I added a trendline to this histogram which looks like a normal curve.
(source: sourceforge.net)
(it is the image all the way to the left)
I would like to know how I can identify a datapoint on the trendline
Is there a tool that does this? The solution can be in VBA if it needs to be.
Upvotes: 2
Views: 1076
Reputation: 16899
If you format the trendline, you can display the equation for the trendline on the chart. You can then copy the equation into a cell and for any value of x you input, you can calculate the y value.
EDIT
I used this VBA code to programatically retrieve the equation from the trendline. Maybe it will help.
Sub ChartStuff()
Dim cht As Chart
Set cht = Charts("Chart1")
Dim ser As Series
Set ser = cht.SeriesCollection(1)
Dim tnd As Trendline
Set tnd = ser.Trendlines(1)
MsgBox (tnd.DataLabel.Caption)
End Sub
EDIT
To move the chart so that it is its own sheet, not an object on a worksheet, right-click on the chart object, choose the 'Move Chart' option, and select the 'New Sheet' radio button. This will create a new tab in your workbook that is only the chart. You can then refer to it by the name on the tab.
Upvotes: 4
Reputation: 4606
You could take your points put them into a different graph and then extract the trend line equation. You could also use Excel's line estimate function "Linest".
Here's a few resources on it:
http://newtonexcelbach.wordpress.com/2011/01/19/using-linest-for-non-linear-curve-fitting/
http://newtonexcelbach.wordpress.com/?s=linest
Hope this helps!
Upvotes: 1