How to simulate missing data at random(MAR) in matlab

Hi,

I would like to simulate missing data at random(MAR).

I do have a code on how to create a missing completely at random (MCAR).

Could anyone suggest me how to simulate / create missing data at random (MAR).

Below are the sample data:

fData = [ 3.6 79; 1.8 54; 3.333 74 ;2.283 62; 4.533 85; 2.883 55; 4.7 88 ;3.6 85 ;1.95 51 ;4.35 85 ;1.833 54; 3.917 84; 4.2 78; 1.75 47; 4.7 83; 2.167 52; 1.75 62; 4.8 84; 1.6 52; 4.25 79; 1.8 51; 1.75 47; 3.45 78; 3.067 69; 4.533 74; 3.6 83; 1.967 55; 4.083 76; 3.85 78; 4.433 79; 4.3 73; 4.467 77; 3.367 66; 4.033 80; 3.833 74; 2.017 52; 1.867 48; 4.833 80; 1.833 59; 4.783 90 ];

[n,dim]=size(fData);

Let say, fData(:,2) are missing if fData(:,1) values are >4.5?

Thank you in advance