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Variable Order Derivatives

version (139 KB) by Duarte Valério
Functions for implementing fractional or complex order derivatives, when the order changes with time


Updated 10 May 2010

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These functions calculate fractional or complex order derivatives, when the order changes with time. Riemann-Liouville, Caputo and Grünwald-Letnikoff definitions are provided; the three variations considered by Lorenzo and Hartley are considered. Fuzzy supervised implementations in Simulink, based upon Oustaloup's Crone approximations, are also provided.

Comments and Ratings (3)

zephyr Lee

problem occured when using constant alpha(t)=1 in vod1RL ,solved by skipping the integration part and going straight to differentiation.
please consider updating this valuable file.

thanks for sharing

I can not use vodRL and here is the error message: Index exceeds matrix dimensions.


Files for variable order, linear phase Crone approximations have been added.

1) A nasty bug affecting variable complex order derivatives was fixed. 2) C^\infty interpolation of zeros and poles now uses exact Crone formulas only.

Required function gamma.m (from now included.

Simulink files for complex orders now provided.

MATLAB Release Compatibility
Created with R2007b
Compatible with any release
Platform Compatibility
Windows macOS Linux

Inspired by: Gamma