A linear least squares method for fitting noisy unimodal functions such as indicator-dilution curves with piecewise stretched exponential functions is described. Stretched exponential functions have the form z(t) = ofPev', where LY, & and y are constants. These functions are particularly useful for
An efficient method for smoothing indicator-dilution and other unimodal curves
โ Scribed by J.B. Bassingthwaighte; I.S. Chan; A.A. Goldstein
- Publisher
- Elsevier Science
- Year
- 1988
- Tongue
- English
- Weight
- 553 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0010-4809
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โฆ Synopsis
A mathematical function has been developed for approximating unimodal functions, particularly those which are non-Gaussian, skewed. and incomplete. It is useful as an alternative to cubic splines in smoothing noisy experimental data. Particular applications are to indicator-dilution curves and probability density functions of varied form. In its Fortran implementation, SMOEX, it is computationally inexpensive compared to standard cubic sphne smoothing routines and requires less storage to preserve the smoothed function for retrieval or interpolation.
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Reconstruction of the primary indicator-dilution curve is accomplished by exponential curve-fit from a set of points obtained on the downslope of the curve. Curve-fit is simplified by requiring entry of indicator concentrations (Yi) only, where time increments (X t) are made self-generating in the p