There are many ways to accomplish this in MATLAB. Here is one:
% Here are some pretend data
data = rand(445,52);
% Create a randomly ordered vector of indices, then use
% that vector to separate into two groups
idx = randperm(445);
indexToGroup1 = (idx<=100);
indexToGroup2 = (idx>100);
group1 = data(indexToGroup1,:);
group2 = data(indexToGroup2,:);
