# Add noise (random values) to data

I have a data set(x,y,z) corresponding to a hemisphere, to which I want to add some controlled noise (random values) to make the x,y,z values diverge.

data = Flatten[ Table[{i, j, i^2 + j^2}, {i, -10, 10, 1}, {j, -10, 10, 1}], 1]

The above is a 3 coordinate set (x,y,z) values for a hemisphere. How do I add random noise to it?

Thank you

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What do you mean by "to make the x,y,z values diverge."? – Dr. belisarius Jan 21 '13 at 4:15
Flatten[ Table[{i, j, i^2 + j^2 + RandomReal[{-10, 10}]}, {i, -10, 10, 1}, {j, -10, 10, 1}], 1];? – Dr. belisarius Jan 21 '13 at 4:18
Ahh sorry.. the above code gives me 3 points = (x,y,z) and I want to add noise to x,y,z, that is some random values (range 0 - 5) to x,y,z – Mun Jan 21 '13 at 4:26
maybe a function that add some random values to each point? – Mun Jan 21 '13 at 4:28
noisydata = # + RandomReal[5, 3] & /@ data;? – kglr Jan 21 '13 at 4:30

 data = Flatten[Table[{i, j, i^2 + j^2}, {i, -10, 10, 1}, {j, -10, 10, 1}], 1];