You reuse the same syntax. I created a general one so that you can enter the desired parameters:
% Syntax:
% u = min(1, max(0, "Linear Line function"));
t = linspace(0, 25, 251);
ramp_start = 10;
ramp_end = 15;
u = min(1, max(0, -1/(ramp_end - ramp_start)*(t - ramp_end)));
plot(t, u, 'linewidth', 1.5), grid on, ylim([-1 2])
