The Origin Forum
File Exchange
Try Origin for Free
The Origin Forum
Home | Profile | Register | Active Topics | Members | Search | FAQ | Send File to Tech support
 All Forums
 Origin Forum
 Origin Forum
 Fitting of complex equation - non linear fit

Note: You must be registered in order to post a reply.
To register, click here. Registration is FREE!

Screensize:
UserName:
Password:
Anti-Spam Code:
Format Mode:
Format: BoldItalicizedUnderlineStrikethrough Align LeftCenteredAlign Right Horizontal Rule Insert HyperlinkUpload FileInsert Image Insert CodeInsert QuoteInsert List
   
Message:

* HTML is OFF
* Forum Code is ON
Smilies
Smile [:)] Big Smile [:D] Cool [8D] Blush [:I]
Tongue [:P] Evil [):] Wink [;)] Clown [:o)]
Black Eye [B)] Eight Ball [8] Frown [:(] Shy [8)]
Shocked [:0] Angry [:(!] Dead [xx(] Sleepy [|)]
Kisses [:X] Approve [^] Disapprove [V] Question [?]

 
Check here to subscribe to this topic.
   

T O P I C    R E V I E W
didny Posted - 08/25/2017 : 12:19:50 PM
Origin Ver. and Service Release (Select Help-->About Origin): 9.0
Operating System: Win 7 x64

Hello,

I have an issue with fitting function to dataset. The only software which was able to fit the curve for profit for Mac. My faith is OriginPro is strong and I hope it is also possible to fit it with Origin :)

Equation is related to unfolding of protein which has intermediate state which also unfolds. The problem is that origin doesn't want to work with equation which also depends on other equations:

amp1=((a1*exp(a2*x))*((a5*exp(a6*x))+(a7*exp(a8*x))))+((a3*exp(a4*x))*(a7*exp(a8*x)));
amp2=-((a1*exp(a2*x))+(a3*exp(a4*x))+(a5*exp(a6*x))+(a7*exp(a8*x)));
y=ln(0.5*(-amp2-(sqrt(amp2^2-4*amp1))))

When I tried to fit all parameters in one equation this was not possible to find result by Origin. Is there way to calculate the the fit using all 3 equations? i would be very grateful for some hints!

Best regards,
Dawid
2   L A T E S T    R E P L I E S    (Newest First)
didny Posted - 08/28/2017 : 09:01:10 AM
It works! Great, thanks. It is really cool that I don't have to use this Pro Fit anymore ;)

Best,
Dawid
arstern Posted - 08/25/2017 : 2:39:12 PM
Hi,

Yes Origin can fit with using multiple equations. When using the Fitting Function Builder make sure to select Equations under Function Type.

Independent variable: x
Dependent variable: y

parameters or constants
: a1, a2,a3,a4,a5,a6,a7,a8

You will then input all 3 equations into the Function Body.

If you get an error when selecting Quick Check, please provide more information on how you are setting up your parameters/constants.

Thanks,
Aviel
OriginLab

The Origin Forum © 2020 Originlab Corporation Go To Top Of Page
Snitz Forums 2000