I'm looking for how to build a zero phase low pass filte. For example: h = fdesign.lowpass(Fpass, Fstop, Apass, Astop, Fs); Hd = design(h, 'ifir'); do a good job to easily create a filter operator, that works fine with filter. But there is a big offset when I use the "filter" command. y = filter(Hd,time-series-data);
"filtfilt" .... would avoid this offset, but doesn't like this filter operator. So my question is how, create as easily such a low pass filter operator, accepted by "filtfilt" or how to create otherwise a zero phase low pass filter ?