After the second step, you get:
vec =
99 91 83 75 67 59 51
98 90 82 74 66 58 50
97 89 81 73 65 57 49
96 88 80 72 64 56 48
95 87 79 71 63 55 47
94 86 78 70 62 54 46
93 85 77 69 61 53 45
92 84 76 68 60 52 44
Third step: (length(size(vec(:,3)))) equals to 2 if you keep dissecting it. Basically, all columns i.e. vec(:,3) have a size of 8 x 1. And length of that "size" is 2.
And thus, you arrive at vec(2). Which is 98 as I indicated above.
