how to accumulate vector

I have following code

for i=1:1000
a=[b(i) c(i) d(i) e(i)]
end

I want accumulate value of a for every i I am adding line

f(i)=a

before end but its showing error

Answer 1

[KSSV]

a = zeros(1000,4) ;
  for i=1:1000
  a(i,:)=[b(i) c(i) d(i) e(i)]
  end

[Jay Hanuman]

yes works