mutiplying vector of different size?

here is what i got

a=linspace(1,1,4); b=linspace(1,1,20);

when i try c=a*b i get a error message saying " ??? Error using ==>mtimes Inner matrix dimensions must agree."

I know this is because a is 4 columns while b has 20 columns, but I don't know how else to define a and b to allow them to multiply. I am trying to find all possible values of c

Answer 1

[bym]

is this what you want?

a =

       1     2     3     4

b =

    Columns 1 through 14

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

    Columns 15 through 20

      15    16    17    18    19    20

>> a.'*b

ans =

    Columns 1 through 14

       1     2     3     4     5     6     7     8     9    10    11    12    13    14
       2     4     6     8    10    12    14    16    18    20    22    24    26    28
       3     6     9    12    15    18    21    24    27    30    33    36    39    42
       4     8    12    16    20    24    28    32    36    40    44    48    52    56

    Columns 15 through 20

      15    16    17    18    19    20
      30    32    34    36    38    40
      45    48    51    54    57    60
      60    64    68    72    76    80

Answer 2

[Walter Roberson]

[A,B] = ndgrid(a,b);
c = A .* B;