and https://www.mathworks.com/help/matlab/math/parameterizing-functions.html (you find this as a link in doc ode45 also)
function am = f(t, y, w)
am = [y(2); -14.7 * sin(y(1)) + sin(1.9*t)];
end
Now call the integrator like:
w = 4;
fcn = @(t, y) f(t, y, w);
ode45(fcn, tspan, y0);