How to set a column vector as a legend name within multiple plots?

I have a for loop that creates a figure with 5 plots. I am trying to set a legend so that each plot says "A = 0", "A = 4", "A = 8", etc.

This is the code I have so far:

figure
hold on
for i = 1:N

a1 = [0;4;8;12;16];
x = data(:,2);
v = data(:,4);
v1 = abs(v);

plot(x,v1,'color',rand(1,3))
title('Velocity Distribution')
xlabel('x/c')
ylabel('v')
legend(strcat('Alpha=',num2str(a1')))
end

However, when I do this it doesnt give me 5 legends. It only gives me one legend for one plot:

I want it to read:

(Line 1) A = 0

(Line 2) A = 4

(Line 3) A = 8

Answer 1

[the cyclist]

Don't take the transpose:

legend(strcat('Alpha=',num2str(a1)))

[Andrew Lackey]

Thank you!