Plot not generating graph

I have the below two functions and script below. I am trying to plot (a,ratio), but my graph is coming up blank? 
Could someone please take a look at what Im doing wrong?

function [CL,CD] = CL_and_CD(a)
%CL_and_CD accepts alpha input,returns two outputs CL/CD
%   Calculates the lift and drag co-efficients "CL" & "CD"
CL = (4.47*(10^-5*(a.^3))+(1.15*(10^-3)*(a.^2))+(6.66*(10^-2).*a)+1.02*(10^-1));
CD = (5.75*(10^-6*(a.^3))+5.09*(10^-4*(a.^2))+1.81*(10^-4.*a)+1.25*(10^-2));
end

function [ratio] = L_to_D(CL,CD)
%L_to_D accepts two inputs and returns one output
%Accepts inputs for CL & CD, and produces the Lift to Drag ratio.
ratio= CL/CD;
end


%Input
a=(-2:0.1:22);
%Call to function CL_and_CD
[CL,CD]=CL_and_CD(a);
%Call to function Ratio
[ratio]= L_to_D(CL,CD);
%Plot
plot(a,ratio);
xlabel('Angle of attack (\alpha)');
ylabel('Lift to Drag Ratio');
title('Lift to Drag Ratio by Angle of attack (\alpha)');

Answer 1

[Star Strider]

Do element-wise division in ‘L_to_D’:

ratio= CL./CD;

Then it works and the plotted curve appears!

[azaandria]

Thank you so much. I was going cross eyed trying to figure it out

[Star Strider]

As always, my pleasure!