File Exchange > Data Analysis >    Fit Convolution

How to install and run
Author:
OriginLab Technical Support
Date Added:
11/24/2017
Last Update:
6/12/2025
Downloads (90 Days):
247
Total Ratings:
15
File Size:
400 KB
Average Rating:
File Name:
FitConvolution.opx
File Version:
1.21
Minimum Versions:
2018b (9.55)
License:
Free
Type:
App
Summary:

Perform convolution of the fitting function with the instrument response while performing the fitting.

Screen Shot and Video:
Description:

The App lets you perform convolution of a fitting function with the instrument response while performing the fitting.

Installation

Download the file Fit Convolution.opx, and then drag-and-drop onto the Origin workspace. An icon will appear in the Apps Gallery window.

Operation

  1. Active a worksheet with the first 3 columns containing numeric data.
    1st Column: Sampling
    2nd Column: Signal
    3rd Column: Impulse Response
     
  2. Launch this app by clicking on its icon.
     
  3. Define the signal function f(x).
    f(x) should not include the y offset parameter y0. Turn on Include y Offset Parameter y0 if necessary.
    For example, set the input type as Simple and the f(x) defined as A * exp(-t * x)
    You can save the fitting function as FDF in Convolution category by clicking the Save as... button then you can re-use it later
    1) in Origin's built-in tool Nonlinear Curve Fit, or
    2) in this app by clicking the link in the Signal Function area. The link is available only if the text area is empty. It brings up a select box (if there's any), where you can click OK to confirm the selection or click anywhere outside the box to cancel it.
     
    Default the signal function is defined as Origin C expression. You can change the Expression Type accordingly to support LabTalk expression.
     
  4. Set proper initial values to the parameters and click 1 Iter. to perform fitting once or Fit directly.
     
  5. Click the Report button to generate a report.

Sample OPJU File
This app provides a sample OPJU file. Right click on the Fit Convolution icon in the Apps Gallery window, and choose Show Samples Folder from the short-cut menu. A folder will open. Drag-and-drop the project file FitConvEx.opju from the folder onto Origin. The Notes window in the project shows detailed steps including how to use options X Shift and XYXY for Input Type.
Note: If you wish to save the OPJU after changing, it is recommended that you save to a different folder location (e.g. User Files Folder).

Updates:

v1.21: update description
v1.20: data shift.
v1.10: Support LabTalk expression.

Reviews and Comments:
06/06/2025gzatrybDear Support Team,
Thank you for your reply. I saved the fitting function in Convolution category and I can use it with NLFit. You were right - I can now select any weighting method available in Origin. This is great. Unfortunately, something is wrong with your function – the fitting curve is shifted with respect to my data and I do not know why. When I perform the fit directly through your App this problem does not exist. It only appears when I use your fitting function via NLFit. However, residuals and Chi2 seem to be correct – only the calculated curve (the curve resulting from the convolution integral) is significantly shifted to the right and it does not overlap with my data. This is problematic because I cannot make any visual inspection of the fit quality. Do you know why this happens?

06/05/2025OriginLabHi gzatryb,
You can use Fit Convolution App to save the fitting function as FDF in Convolution category by clicking the Save as... button then you can re-use it in other fitting tool such as NLFit with weight setting.
OriginLab Support

06/04/2025gzatrybI have a question - when this App performs fitting does it use weights? I usually use yfit option for my weights and I would like to use it also with this app. Is it possible? Thanks.

03/03/2025 Doesnt work

02/22/2025DYQ97I solve the problems before. But i have a new questions. How can i use this function and sent parameters to it in the LabTalk script？I have too many data to fit sequentially.

02/11/2025DYQ97Hey there. I have some missing data in y, which is column B under XYXY mode. The fitting is good, but the fitted Y curve is break on the x points which correspoding the missing data in column B. For example, under XYXY mode, I have 100 x points in column A. However, column B contains 50 real data y at first, followed by 10 missing data "--" , and 40 real data y at last. I have a continuous instrumental responce (Col C and D). After the fitting, there are only 90 x points in FitNLCurve->A(X1) with 90 fitted y points in B(Y1). I want to have the whole fitted Y curve, so i make a convolution of the signal function, with the fitted parameters i got before, and the instrumental responce by myself. But the results is different from the FitNLCurve->B(Y1) on the amplitude. Is there any solutions for export the whole continues fitted Y curve?

12/19/2024OriginLabHi CathyDC,
You need to define the signal function and click the Save as... button to re-use it later. We will improve the usability of this app.
OriginLab Tech Support

12/19/2024OriginLabHi CathyDC,
Origin 2022b supports to use this app. We are not sure why the functions do not show up in your app. We suggest you can send your detail question to our support team by sending a ticket in this page: https://www.originlab.com/restricted/support/newticket.aspx?c=3
OriginLab Tech Support

12/17/2024CathyDCDoes not work on 2022b
functions do not show up etc

12/17/2024CathyDCDoes not work on 2022b
functions do not show up etc

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