TickMode on MATLAB plot

figure(1);

[db, mag, pha, w] = freqs_m(cs, ds, 10e3);

subplot(3, 1, 1); plot(w/pi, db);

title('Magnitude in dB : Analog Butterworth Lowpass Filter');

xlabel('Analog frequency in pi units'); ylabel('Decibels');

axis([0, 10e3, -70, 5]);

set(gca, 'XTickMode', 'manual', 'XTick', [OmegaP/pi, OmegaS/pi, 10e3]);

set(gca, 'YTickmode', 'manual', 'YTick', [-As, -Rp, 0]);

grid;