Analog butterworth to digital - bilinear transform In my previous question I've designed analog butterworth filter (poles own calculated). But now I would like to transform it to digital domain. I'm using bilinear transformation but not all is clear for me. Please look at my script below:

clc, clear all, close all;

%ANALOG BUTTERWORTH FILTER DESING
%https://engineering.purdue.edu/~ee538/AnalogFilterDesigns.pdf

%Butterworth LP with -3dB at fc and N order and G gain

wc = 1000;   %cut off frequency
N = 2;      %filter order
G = 1;      %filter gain 

%analog filter design with prewarped frequency
%poles and zeros 

%frequency normalizing and prewarping
wc = 2*tan(wc/2);

%poles searching
for k = 0:N-1
   sk(k+1) = wc*exp(j*(pi/2))*exp(j*(2*k+1)*(pi/(2*N)));
end

[NUM,DEN] = zp2tf([],sk,G);
b0 = DEN(end)*G      %gain normalization  

Hs = tf(b0,DEN)

figure();
freqs(b0,DEN)
title('lowpass filter with pre-warped frequency visualization')
figure();
plot(sk./10^2, 'x')
xlim([-10,10]);
title('Poles placement in s-plane')

%continuous to digital conversion
[NUMD,DEND] = bilinear(b0,DEN,1);

fvtool(NUMD,DEND)


Results looks like below:


I'm sure that is not what I want, because I have nowhere applied frequency sampling that is interesting me. I'm not also sure if I've done prewarping well.

EDIT: frequency response for ws = 2000 in bilinear transformation:
look at MATLAB bilinear().  you are specifying fs=1 in your call to it.

if you're gonna do any digital filtering, sometime, somewhere you need to commit to a sampling frequency and you haven't yet.