| | 1 | = Format of filter files = |
| | 2 | |
| | 3 | The filter files are line oriented, that means there is one information entry per line. Blank lines are not allowed! The format of the filter files is as follows: |
| | 4 | |
| | 5 | == FFT filter == |
| | 6 | |
| | 7 | * All lines at the beginning of the file starting with exclamation sign ! are comments and ignored by the program. |
| | 8 | * The first data line is a magic number and must be 1357913578 |
| | 9 | * The next data line contains the number 1, which is an ID for FFT filters. |
| | 10 | * Normalization value (real number), which is multiplied to the output samples of the filter. |
| | 11 | * Number of zeros z (integer) |
| | 12 | * z lines following with one zero each in the format (<real-part>,<imag-part>). Both parts of a complex conjugate pair must be specified. |
| | 13 | * Number of poles p |
| | 14 | * p lines following with one pole each in the same format as zeros. |
| | 15 | |
| | 16 | [http://www.seismic-handler.org/portal/browser/SH_SHM/trunk/filter/GRFO_S%2BSRO_LP.FLF Example of an FFT filter file]. |
| | 17 | |
| | 18 | == Recursive filters == |
| | 19 | |
| | 20 | * All lines at the beginning of the file starting with exclamation sign ! are comments and ignored by the program. |
| | 21 | * The first data line is a magic number and must be 1357913578. |
| | 22 | * The next data line contains the number 3, which is an ID for recursive filters. |
| | 23 | * Sample rate for which this file is valid (real number) |
| | 24 | * Normalization value (real number), which is multiplied to the output samples of the filter. |
| | 25 | * Number of numerator coefficients n (integer) |
| | 26 | * n lines following, one coefficient (real number) in each. |
| | 27 | * Number of denominator coefficients d (integer) |
| | 28 | * d lines following, one coefficient per line. |
| | 29 | * Optional following other stages of the filter, new stage indicated by a line containing a single @. |
| | 30 | * Additional stages are repeating the entries 'ID number 3' until denominator coefficients. |
| | 31 | |
| | 32 | [http://www.seismic-handler.org/portal/browser/SH_SHM/trunk/filter/20HZ_GRSN_S%2BSRO_LP.FLR Example of a recursive filter file]. |
| | 33 | |
| | 34 | back to [ShmDocIndex documentation index] |
