Array processing code

Usage Questions
1

I did not understand the following segment of code used in the array_processing source file.

# generate plan for rfftr
    nfft = next_pow_2(nsamp)
    deltaf = fs / float(nfft)
    nlow = int(frqlow / float(deltaf) + 0.5)
    nhigh = int(frqhigh / float(deltaf) + 0.5)
    nlow = max(1, nlow)  # avoid using the offset
    nhigh = min(nfft // 2 - 1, nhigh)  # avoid using nyquist
    nf = nhigh - nlow + 1  # include upper and lower frequency
    # to speed up the routine a bit we estimate all steering vectors in advance
    steer = np.empty((nf, grdpts_x, grdpts_y, nstat), dtype=np.complex128)
    clibsignal.calcSteer(nstat, grdpts_x, grdpts_y, nf, nlow,
                         deltaf, time_shift_table, steer)
    _r = np.empty((nf, nstat, nstat), dtype=np.complex128)
    ft = np.empty((nstat, nf), dtype=np.complex128)
    newstart = stime
    # 0.22 matches 0.2 of historical C bbfk.c
    tap = cosine_taper(nsamp, p=0.22)

If I have frqhigh=0.1 Hz, with the above code segment, the code wouldn’t run properly right? I am really lost about what’s done here. Any help would be appreciated.
Thank you