Set or query the cutoff frequency (ωc1) of the low pass/high pass filter or cutoff
frequency 1 (ωc1) of the band pass/band stop filter. The default unit is Hz.
Related to the filter type
LPASs|BPASs|BSTOP: 0.005 x screen
sample rate
HPASs: 0.1 x screen sample rate
 When the type of the filter is set to LPASs (low pass) or HPASs (high pass), you
need to set one cutoff frequency (ωc1). At this time, the range of <freq1> is from
(0.005 x screen sample rate) to (0.1 x screen sample rate), with a step of (0.005 x
screen sample rate). Wherein, Screen Sample Rate = 100/Horizontal Timebase.
 When the type of the filter is set to BPASs (band pass) or BSTOP (band stop), you
need to set two cutoff frequencies. Send this command to set cutoff frequency 1
(ωc1); and send the :MATH:FILTer:W2 command to set cutoff frequency 2 (ωc2).
At this time, the range of <freq1> is from (0.005 x screen sample rate) to (0.095 x
screen sample rate), with a step of (0.005 x screen sample rate). Wherein, Screen
Sample Rate = 100/Horizontal Timebase.
Note: Cutoff frequency 1 (ωc1) must be lower than cutoff frequency 2 (ωc2).
:MATH:FILTer:W1 1000000 /*Set the cutoff frequency of the low pass filter to
1MHz*/
:MATH:FILTer:W1? /*The query returns 1.000000e+06*/