FilterM 1.0

FilterM, FiltFiltM: Fast digital filterThese functions are compatible to MATLAB's FILTER and FILTFILT commands,but they are faster (see screenshot): FilterM: 30%-40% of FILTER runtime FiltFiltM: 4%-20% of FILTFILT runtimeADDITIONAL FEATURES:- The dimension to operate on can be specified for FiltFiltM.- FilterM can process the signal in backward direction. (This is the main part of the acceleration of FiltFiltM, because it avoids to reverse the signal two times.)- For signals of type SINGLE, the intermediate values are stored in DOUBLE precision to increase the accuracy. The output is converted to SINGLE again.- The Signal Processing Toolbox is *not* needed.CALLING: Y = FiltFiltM(b, a, X, Dim) [Y, Zf] = FilterM(b, a, X, Zi, Dim, Reverse) b, a: Filter parameters as DOUBLE vectors. X: Signal as DOUBLE or SINGLE vector or array. Zi, Zf: Initial and final conditions as DOUBLE or SINGLE array. Optional, default: Zeros. Dim: Dimension to operate on. Optional, default: 1st non-singelton. Reverse: Flag to process the signal in reverse direction. Optional, default: FALSE. Y: Filtered signal, same size and type as X. While FilterM filters in forward direction, FiltFiltM processes the signal forward and reverse direction for a zero phase distortion.INTENTION:To accelerate my FEX submission FiltFiltM, I've implemented a filter asC-Mex, which works in reverse order. To my surprise this was faster thanrunning Matlab's FILTER forward, e.g. 3.7 times for a [10000 x 1] vector,5th order Butterworth filter (Matlab 2009a, WinXP 32 bit, single core).Therefore I've expanded the Mex such that the direction can be definedas input. The algorithm is a direct form II transposed structure.A future version will be mutli-threaded.INSTALLATION:Setup the compiler if not done before: mex -setup.Auto-compilation: Call FilterM without inputs to start the compilation.A pre-compiled Mex can be downloaded: http://www.n-simon.de/mexRun the unit-tests uTest_FilterM and uTest_FiltFiltM to check validity and speed.Tested: Matlab 6.5, 7.7, 7.8, WinXP, 32bit Compiler: LCC2.4/3.8, BCC5.5, OWC1.8, MSVC2008Assumed Compatibility: higher Matlab versions, Mac, Linux, 64bitThis is faster and more powerful than my former submission "FiltFiltM", which will be removed soon

Requirements:	No special requirements
Platforms:	Matlab
Keyword:	Algorithm,  Defined,  Direct,  Expanded,  Input,  Setup,  Single,  Structure,  Transposed
Users rating:	0/10