RESPITE: The CASA Toolkit Page: Documentation: Block Library Index:Filter |

Filter

** Filter** is a "Direct Form II Transposed" implementation of the standard difference equation:

whereA(1)*y(n) = B(1)*x(n) + B(2)*x(n-1) + ... + B(nB+1)*x(n-nB) - A(2)*y(n-1) - ... - a(nA+1)*y(n-nA)

If *A(1)* is not equal to 1, ** Filter** normalizes the filter coefficients by

nA A(1) A(2) A(3) ... A(nA)

nB B(1) B(2) B(3) ... B(nB)

For example, the file containing:

3 1.0 0.5 0.1 2 0.2 0.2would correspond to the difference equation:

y(n) = 0.2*x(n) + 0.2*x(n-1) - 0.5*y(n-1) - 0.1*y(n-2)

Inputs |
Meaning | Sample | 1-D frame | 2-D frame |
---|---|---|---|---|

in1 |
signal (i.e. x) |
Yes | Yes | Yes |

Outputs |
Meaning |
---|---|

out1 |
filtered signal (i.e. y) |

Parameters |
Type | Default | Meaning |
---|---|---|---|

FILENAME |
string | - | File storing filter A and B coefficients |

A |
FloatVector | - | Filter A coefficients |

B |
FloatVector | - | Filter B coefficients |

Documentation for CTKv1.1.4 - Last modified: Thu Jun 28 11:27:41 BST 2001