At first, why is the size of the array 300*3 ? Don't you mean 100*3 ?
If so, I'd like you to try the following manners.
1): Create the coordinate for x and y, respectively.
x=(0.1:0.1:1)'
y=(0.1:0.1:1)'
2): Convert the size of "C" from 100*1 to 10*10.
C=(1:100)'; % Showing just an example.
>> CC=reshape(C,10,10)
CC =
1 11 21 31 41 51 61 71 81 91
2 12 22 32 42 52 62 72 82 92
3 13 23 33 43 53 63 73 83 93
4 14 24 34 44 54 64 74 84 94
5 15 25 35 45 55 65 75 85 95
6 16 26 36 46 56 66 76 86 96
7 17 27 37 47 57 67 77 87 97
8 18 28 38 48 58 68 78 88 98
9 19 29 39 49 59 69 79 89 99
10 20 30 40 50 60 70 80 90 100
3): Illustrate figure.
contour3(x,y,CC)
and you'll obtain,
