This Python script generates a filter mask (frequency response) for yapp_filter. The format of the filename is yapp_mask_nfft_tsamp_lower_upper.dat. The mask coefficients are signed bytes.

Usage:

The options are:

• -h or --help: Display this usage information.
• -n or --nfft nfft: Length of the Fourier transform (default is 4096).
• -t or --tsamp tsamp: Sampling time in seconds.
• -l or --lower freq: Lower cut-off frequency in Hz (default is 0.1 Hz).
• -u or --upper freq: Upper cut-off frequency in Hz (default is 1000 Hz).
• -g or --graphics: Turn on plotting.

The flag -t (or --tsamp) is a required argument.

Example:

The following generates a filter mask to run yapp_filter with 16384 FFT points, with a lower cut-off frequency of 1 Hz and an upper cut-off frequency of 100 Hz, for data with a sampling time of 10 microseconds. It creates a file named yapp_mask_16384_0.0001_1.0_100.0.dat in the current working directory, and also displays a plot of the filter mask.