Integration of Origin C into the Nonlinear Least Squares Fitter
Origin
C has been fully integrated into the Nonlinear
Least Squares Fitter (NLSF) starting with Origin 7 SR2.
By integrating Origin C into the NLSF, the process of defining a
custom, real-world fitting function has been made more flexible,
intuitive and user-friendly. By using Origin C to define your function,
performance and speed are dramtically increased compared to previous
versions.
The advantages to the union of the NLSF and Origin C are numerous:
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Fitting is up to 20 times faster than in previous versions
when you define your function using Origin C.
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Custom parameter initialization routines for estimating the
initial values for the parameters of the function. These routines
can be developed directly in Code Builder and execute automatically
when fitting.
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The function can be defined directly in Code Builder, Origin
C's programming interface. This allows you full access to
Code Builder's capabilities. They include color-coded editing,
syntax checking, and a modern, full-featured debugger (a first
for the scientific software industry). Code Builder's debugging
capabilities come in the form of break points, single step
execution [including step in, step over, step out, etc.],
and variable watch windows.
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Technical Specifics
About the NLSF
The nonlinear least squares fitter (NLSF) in Origin ships with
nearly 200 predefined fitting functions organized in various categories,
such as Peak Functions, Chromatography functions, etc. In addition
to these built-in fitting functions, Origin users can define their
own custom functions to perform nonlinear curve fitting.
About Origin C
Origin C, Origin 7's new programming language, is an ANSI C compatible
programming language that allows researchers to program useful routines
in a familiar programming language. Routines can include simulation,
data file processing, special functions, and more.
About the Integration of the NLSF and Origin C
To bring the two features together, the NLSF has been updated to
include controls for defining fitting functions in Origin C as well
as editing them in Code Builder. The fusion also brought about the
creation of a new NLSF window called Parameter Initializations.
This window allows you to define parameter initializations in Origin
C in the same way you can define the actual function.
Defining your function
When defining a user-defined function in the NLSF, you can elect
to define it in Origin C by enabling a 'Use Origin C' (formerly
named 'Compile before use') check box. The syntax of the function
can then be checked using Code Builder by clicking on the Edit
in Code Builder button.
If the function yields an error, you can test it by enabling
break points at specific problem areas. You can then execute the
function and step through it using the Debug toolbar and the Variables
and Watch windows.
View the Define New Function dialog showing an Origin C function
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View the function being edited in Code Builder Details
Automatically initializing your function parameters
This environment also allows the user to develop custom parameter
initialization routines for estimating initial values for the
parameters of their custom function. Many useful Origin C functions,
such as min, max, FWHM, etc. are provided to the user, who may
then use combinations of these functions to obtain properties
of their data sets, to determine initial parameter estimates for
their fitting functions.
Enable the Use Origin C check box and click on the Edit in Code
Builder button on the Parameter Initializations page. An Execute
button is also provided which allows you to execute the Parameter
Initializations code any time you want, effectively reinitializing
the parameters.
View the Parameter Initializations dailog Details
View the parameter initializations being edited in Code Builder
Details
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