| T O P I C R E V I E W |
| bayoguz |
Posted - 08/06/2017 : 8:46:36 PM
Hello dear members
I have used OriginLab 9.0.0 (32-bit) on Windows 7
I havn't yet succeded to run y=y0*exp(-A*x) on exponential fit
where y0 is the value of y at x= the first value, =1 or y0= ymax) and A is an unknown constant. (exp is exponential)
I have plotted y vs x and then I have tried to do an exponential curve under the real curve
Maybe it is very easy but I am a new user
I would like to learn which fonction is very close my pilot |
| 1 L A T E S T R E P L I E S (Newest First) |
| JacquelineHe |
Posted - 08/07/2017 : 02:08:06 AM
Hi,
If I do not misunderstand, your original data is curve (k). But you want to fit a curve (l) by the function y=y0*exp(-A*x), right?
1. I am not sure do you have the dataset of three curve (k), (l) and (m).
If you have curve (l) dataset, you can fit it by the function directly.
2. For the fitting function y=y0*exp(-A*x)
a) You can try to use our build in function: y = a*exp(b*x)
http://www.originlab.com/doc/Origin-Help/Exp2PMod1-FitFunc
“a” is y0, and “b” is -A
If the value of “a” have been known, you can fix this parameter value in “Parameters” tab in NLFit dialog.
http://www.originlab.com/doc/Origin-Help/NLFit-Dialog-ParaTab
b) If you want to define a new function for it, then you can refer to the Tutorial and Help page:
http://www.originlab.com/doc/Tutorials/UserDef-FitFunc
http://www.originlab.com/doc/Origin-Help/UserDef-FitFunc
Thanks
Jacqueline
OriginLab |
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