| Author |
 Topic  |
|
|
mdonoghu
3 Posts |
 Posted - 12/02/2010 : 2:15:25 PM
|
Origin Ver. and Service Release (Select Help-->About Origin): 8.1 SR3
Operating System: Windows 7
There's probably something painfully obvious that I'm missing....I recently upgraded from Origin 7.5 and am attempting to apply a linear fit to my data. I have been selecting the graph where it's plotted, and telling it to fit. No fit is generated, though. A table pops up in the plot and worksheets are added to my data file; however all the boxes (e.g. slope, intercept, R) are empty. Any insight would be much appreciated. |
|
|
greg
USA
1378 Posts |
Posted - 12/02/2010 : 3:17:11 PM
|
It sounds like the active dataset may not have numeric data or possibly all the data has been masked. I don't know why that happens in your case, but I can create an example where exactly that happens.
In a new worksheet, add a third column and fill columns A and C with numbers , but leave column B empty.
Select columns A through C and plot.
Since B was selected it will be included in the plot although nothing will show except the Legend. Since B is the first of two Y datasets in the plot, it is the active dataset and will automatically be picked up by the Linear Fit dialog. As in your case, the fit will be empty.
Check the Input Data branch in the Fit Linear report to see exactly what data was fitted (including range).
Check the Masked Data branch to see if any data was masked.
Check the Bad Data branch to see if there were any missing values. |
 |
|
|
mdonoghu
3 Posts |
Posted - 12/02/2010 : 3:25:51 PM
|
So it has something to do with the y-errors I was trying to include for weighting. Without that data it's fine.
There was no missing data, no masked data, all the input data was listed correctly. |
|
|
|
snowli
USA
1386 Posts |
Posted - 12/02/2010 : 4:11:06 PM
|
It could be that there is 0 in your Y Error column so it can't be used as instrumental weight. You can press F1 in the Linear Fit dialog to see how the weight is calculated.
In 8.1, we didn't show the reason why it failed in result sheet. We have improved it in Origin 8.5 so when there is 0 in YError and you use instrumental weight, warning message will be given and message will be given at the footnote of result sheet.
Thanks, Snow Li
OriginLab Corp.
|
|
|
|
mdonoghu
3 Posts |
Posted - 12/02/2010 : 4:19:49 PM
|
Thanks!
The 0 error is the source of the problem.
Darn my consistent results :) |
|
|
| |
Topic |
|
|
|
No output on linear fit