Help Please! I'm plotting curve for (7,4) hamming code.

I'm doing (7,4) hamming code can anybody tell me where I'm doing mistake for that I'm unable to get plot for this code? And how can I do convolutional performance in this code?

close all, clc, clear all; 
num_bits = 8;
p = 0:0.0001:0.1
for a = 1:length(p);
genmat = hammgen(3)
n = 7; % Codeword length
k = 4; % Message length
data = randi([0 1],1,num_bits) % Random matrix
encData = encode(data,n,k,'hamming/binary')
nz = bsc(data,p(a))
data(4) = ~data(4)
decData = decode(encData,n,k,'hamming/binary')
numerrs(:,1) = biterr(data,decData)
ber = numerrs/num_bits
end 
plot(p,ber,'g--o')
xlim([0 0.1]) 
ylim([0.0001 1])
legend('hamming (7,4)')
xlabel('p crossover probability for the bsc')
ylabel('Probability of error')
title('19TL49')
grid on

Answer 1

[Torsten]

ber(a) = numerrs/num_bits;

instead of

ber = numerrs/num_bits;