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Main purpose of DMFitter ActiveX control is to provide sophisticated numeric
calculation algorithms, namely linear and non-linear (Levenberg-Marquardt)
least-squares fitters in the form of easily reusable component. Unlike other
popular numeric algorithms (simple statistics, spline interpolation, etc) curve
fitting is much more complicated so that developers can save a lot of efforts.
If you are not familiar with the basic concepts of the regression analysis, you
can get started with
DM2003 visual curve fitting tools. Although DMFitter ActiveX control is not
a part of Data Master 2003 and can be used independently, in fact both products
share the same source code base.
Data Master 2003 software provides almost the same set of features available through interfaces of DMApplication object. However, if your application based on another host platform (e.g. Microsoft Excel), or if you don't intend to use full set of DM2003 features, you may prefer compact in-process ActiveX control instead. This solution has following advantages:
And, of course, DMFitter ActiveX control is freeware like DM2003.
Host platforms: any COM/ActiveX compatible hosts, including MS Visual Basic, Borland Delphi, MS HTML (Internet Explorer), Data Master 2003, Windows Scripting Host (WSH), MS Office VBA, VBScript, JavaScript and so forth. Example applications for MS Excel, VB.Net, C#, DM2003, MSIE, Delphi, VBScript, JScript and WSH are included.
Implemented algorithms:
User-defined models: wide set of internal functions and operators and up to 25 fitting parameters for LM fitter. In addition, you can define custom class to calculate your NLSF expression and partial derivatives analytically (see TestFitObject.htm demo) or perform calculations in the event handlers. This feature significantly increases NLSF robustness and performance.
Event support: NLSF operations are extremely processor-intensive and may take a lot of time. DMFitter object fires OnProgress event every time when it finishes LM iteration, providing you with a number of completed iterations and current values of fitting parameters. So that, you can easily create animated visual feedback for your users (see TestAniLMFit.* demos for more details).
Also you can use event handlers to perform analytical calculations of user-defined linear basis functions (see TestLinearEFit.htm demo) and NLSF function and partial derivatives (TestLMFitEvents.htm and TestLMFitEJS.htm).
Additional options allow you to specify Chi2 and parameters convergence thresholds, control parameter step for calculating derivatives, temporarily fix fitting parameters and apply point weighting.
Multidimensional independent variable is supported in the LM fitter:
Y=Y(X1,
Installation of DMFitter ActiveX control is very simple and doesn't require special installer software. Unpack the contents of the archive into some folder on your hard drive and run COM registration utility from the command prompt as shown below:
regsvr32 fitter.dll
Keep in mind that on Windows NT systems installation folder must have correct security settings, and you also must log in with appropriate access rights. Uninstall is also very straightforward - just type in the command prompt:
regsvr32 /u fitter.dll
and after you will see confirmation message you can delete the whole contents of the installation folder. If you intend to include fitter.dll unit into your setup, don't forget to mark this file for self-registration, or configure your setup so that it will be correctly registered.
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| DMFitter | |||
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| IDMFitter | IDMFitterEvents | ||
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