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filters.cpp File Reference

A collection of filtering functions for processing A-scans. More...

Defines

Functions

Detailed Description

A collection of filtering functions for processing A-scans.

$Id: filters.cpp,v 1.1 1999-03-05 16:31:33-05 ljb Exp ljb $ $Revision: 1.1 $

$Log: filters.cpp,v $ Revision 1.1 1999-03-05 16:31:33-05 ljb Initial revision

Function Documentation

WORD filter_ab( INT32 *y, INT16 npts, float *a, float *b, INT16 ncoef)

function used to implement digital filter described by coefficients a and b.

Parameters:
y - points to the input data
npts - is the length of input vector.
a - points to filter coefficients.
b - points to filter coefficients.
ncoef - are the number of coefficients.

Filters the data in vector y with the filter described by vectors a and b to create the filtered which is returned in y. The filter is a "Direct Form II Transposed" implementation. Assumes that the coefficient vectors are floats and scaled.

WORD RfFilterLP( INT32 *data, INT16 npts)

This filter is designed to be a lowpass with cutoff at 5MHz.

Parameters:
data - points to the I/O data buffer.
npts - is the length of the buffer.

The details are in the coefficients

WORD RfFilterHP( INT32 *data, INT16 npts)

This filter is designed to be a highpass.

Parameters:
data - points to the I/O data buffer.
npts - is the length of the buffer.

The details are in the coefficients

WORD ViFilter( INT32 *data, INT16 npts, INT16 nfactor)

This filter is designed to be a lowpass with cutoff at 2.5 MHz.

Parameters:
data - points to the I/O data buffer.
npts - is the length of the buffer.
nfactor - is a decimation (downsampling) factor.

The details are in the coefficients

Software written by
Larry Busse of LJB Development
and Bill Glenn, Al Murphy and John Losche of TETRAD Corporation
Documentation generated 3/11/1999