Radiation Pattern - problems in horizontal scaling

Hi there. I'm plotting two radiation patterns to compare them, but according to the solution I was given, they don't seem to scale properly.

The one at the top is the solution, the one at the bottom is mine.

This is my code:

%%Problem 9
N = 10; delta = pi/N;

f = @(x) ((N*sin(delta/2))/(sin(N*(delta/2))))*(sin(N.*x./2)./(N.*sin(x./2)));
theta = linspace(-2,2,300);

% a = 2*pi/3; phi = a*(cos(0.95*theta)-1)-delta;
a = 2*pi/3; phi = a*(cos(theta)-1)-delta;
F = f(phi); F = 20*log10(F); F = real(F);
F(F<-35) = -55;
figure(),plot(1.1*theta,F,'r','LineWidth',2); 
hold on

% a = 20*pi/30; phi = a*(cos(theta)-1)-delta;
a = 23*pi/30; phi = a*(cos(theta)-1)-delta;
F = f(phi); F = 20*log10(F); F = real(F);
F(F<-35) = -45;
plot(theta,F,'b','LineWidth',2); hold off

axis([-1.5 1.5 -60 0])
xlabel('Theta'); ylabel('Normalized AF(dB)');
legend('Ordinary','Hansen Woodyard');

What am I doing wrong? How can I scale the graph horizontally, and "flatten" the top? Is there any info I've left out that could help?

Thank you.