| Author |
 Topic  |
|
|
Rolulu
Germany
4 Posts |
 Posted - 02/26/2018 : 10:12:24 AM
|
Origin Ver. and Service Release (Select Help-->About Origin): 8G.063.988 SR6 v8.0988
Operating System:Windows 10 32-bit
Hi you guys
i have a problem with the ExpDec2 Fitting. I have timeresolved Photoluminescence curve and want to fit the transient to get the 2 Decay times, but with the nonlinear Fit it is not possible to get it right.
I can upload the Data if you like.
Greetings
Lulu |
Edited by - Rolulu on 02/26/2018 10:13:05 AM |
|
|
arstern
USA
237 Posts |
Posted - 02/26/2018 : 10:45:42 AM
|
Hi Lulu,
I'm not exactly sure what you mean by "get the 2 decay times". However, if you are asking to only fit the transient part of the curve. I think the easiest way to do this is to first Select from Toolbar the icon called Selection on Active Plot (the icon with the blue oval with an arrow pointing down) https://www.originlab.com/doc/Origin-Help/Tools-Toolbar
Then select Active graph and select range on graph that you want to fit. This will customize the data range for analysis.
With Graph activated Select Analysis -> Fitting -> Nonlinear Fit -> Select ExpDec2. In the Graph you will see that the fit is only fitting within the selected region (between the red vertical lines). As well when you select Data Selection under Settings within the Nonlinear Fit Dialog, the Input Data specifies the data range from the selected region.
Thanks,
Aviel
OriginLab
|
Edited by - arstern on 02/26/2018 11:38:09 AM |
 |
|
|
Rolulu
Germany
4 Posts |
Posted - 02/26/2018 : 11:32:14 AM
|
HI Avil
i look for the option upload, but maby i am blind, but i didnt find it. I like to do this.
Greetins Lulu |
|
|
|
arstern
USA
237 Posts |
Posted - 02/26/2018 : 11:40:48 AM
|
Hi Lulu,
I recently updated my post. Please see comment above. If this is not what you want, please e-mail your .opj file to tech@originlab.com. That way I can take a look at your data.
Thanks
Aviel |
|
|
|
Rolulu
Germany
4 Posts |
Posted - 02/27/2018 : 05:01:39 AM
|
Hi Aviel
I have uploaded the File to your FTP server. It is named "3or2exponatialFit" there 2 Data sets from the same sample. The First one "normalized 26916" is the 3exponatial Decay. The second colum is the the same sample but without the first 4,5ns so it is only 2exponatial. The Fist decay should be the laser so around 3-4,5ns thats why it is possible to cut this of.
I tried your suggestion but it was not the best fit.
Thanks for your help.
Lulu |
|
|
|
arstern
USA
237 Posts |
Posted - 02/27/2018 : 10:41:36 AM
|
Hi Lulu,
I am not exactly sure if you are trying to fit only the transient part of the data therefore using an exponential fit?
See image below. I fit part of the curve with ExpDec1 by selecting the part of the curve that has an exponential curve trend. If I had selected the data starting from the peak to the last point, then the exponential fit would not work because the curve is no longer exponential.
I was able to fit the entire curve by using the Peak Fitting Function PsdVoigt1. There were other peak fitting functions that also fit this data. However this seemed like a good fit.
Let me know if this helps
Thanks
Aviel |
|
|
|
Rolulu
Germany
4 Posts |
Posted - 03/02/2018 : 04:29:00 AM
|
Hallo Aviel,
big thank you for your help. To cut out several parts were a good Idea. I will try out with the other data. Thank you also for the really quick answers.
Thank you
Lulu |
|
|
| |
Topic |
|
Biexponential Fit on Transiente