Example

> a = rand(2,4)
 a =
        1      0.647     0.0369      0.665  
    0.975      0.333      0.162     0.0847  
> ifft(a)
 matrix columns 1 thru 3
              0.987 + 0i               0.49 + 0i             0.0993 + 0i
             0.0127 + 0i              0.157 + 0i            -0.0624 + 0i

 matrix columns 4 thru 4
              0.375 + 0i
               0.29 + 0i
> imag(ifft(a))
        0          0          0          0  
        0          0          0          0 
> b = rand(4,4)
 b =
    0.204       0.91        0.7       0.96  
    0.167      0.112       0.95      0.915  
    0.655      0.299     0.0918      0.441  
    0.129      0.265      0.902     0.0735  
> ifft(ifft(b)')'
 matrix columns 1 thru 3
              0.486 + 0i       -0.0931 + 0.0502i            -0.011 + -0i
        0.0804 + 0.0484i       -0.128 - 0.00638i       -0.0608 - 0.0376i
             0.0466 + 0i         0.101 - 0.0262i            -0.109 + -0i
        0.0804 - 0.0484i     -0.00398 - 0.00519i       -0.0608 + 0.0376i

 matrix columns 4 thru 4
       -0.0931 - 0.0502i
     -0.00398 + 0.00519i
         0.101 + 0.0262i
       -0.128 + 0.00638i