Adding a row of ones

I want to add a row of ones to the first row of a=[1 2 3 4;5 6 7 8;9 10 11 12; 13 14 15 16]. This 4x4 will become 5x4. Any suggestions?

Answer 1

[Atsushi Ueno]

a = [1 2 3 4;5 6 7 8;9 10 11 12; 13 14 15 16];
b = [ones(1,size(a,2)); a]

b = 5×4

1 1 1 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

[Renea Young]

Thank you