DADiSP Software
Modules - DADiSP/Filters
Digital Filter Design Module
DADiSP/Filters is a menu-driven, digital filtering module that adds complete
FIR and IIR filtering capabilities to DADiSP. DADiSP/Filters allows you
to quickly design, analyse and process both FIR (Finite Impulse Response)
and IIR (Infinite Impulse Response) digital filters from easy-to-use dialogue
boxes or simple one line functions. On-line help and examples are also
provided.
Design, Analyse and Apply
DADiSP/Filters gives you the power to easily build digital filters
that emulate hardware based designs for testing and verification or perform
filtering operations not possible with traditional analog methods. DADiSP/Filters
allows you to remove noise generated during the data collection process.
DADiSP/Filters is the perfect complement to GPIBLab,
DADiSP's acquisition module for collecting data from IEEE-488 based instruments
and DADiSP/AdvDSP,
a sophisticated module for advanced signal processing techniques.
FIR Filters
The FIR module creates linear phase lowpass, highpass, bandpass, bandstop,
multiband, Hilbert transformers and differentiators using the Parks-McClellan/Remez
Exchange optimal design algorithm. The filter order can be specified or
automatically estimated from the particular filter specifications. The
Kaiser Window method is also provided, capable of creating both very high
order FIR filters and extremely tight, narrowband filters.
IIR Filters
The IIR module supports Bessel, Butterworth, Chebychev I, Chebychev
II and Elliptic designs for lowpass, highpass, bandpass and bandstop recursive
filters. The Bilinear transform method is employed and
the resulting IIR coefficients can be determined in optimal multistage
cascade format or traditional Direct form. The module also supports the
Matched-Z transform method to approximate linear phase characteristics
for IIR Bessel filters.
Coefficient Conversion
Filter coefficients can be converted to and from Cascade, Direct and FIR
form and the coefficients can be quantised to emulate DSP chipsets.
Filter Response
The impulse, magnitude, phase and group delay characteristics can be calculated
for any filter. Pole-Zero plots are also supported. Efficent time and
frequency domain filtering algorithms are provided to apply the filter
to any series.
Fully Integrated
The filters module is fully integrated with DADiSP to provide a complete
digital filter design, analysis, display and processing environment. The
DADiSP/Filters user interface is dialogue based, eliminating the need
to memorize argument lists or formulas and allows quick recall of previous
filter designs. The filter coefficients are automatically displayed in
a DADiSP window and can be saved for further use by DADiSP or other programs.
See function list...
| 
