function prefixes = gen_prefixes (suffix, prefix)
if nargin < 1
    suffix = '';
end
if nargin < 2
    prefix = '';
end
tfs = {'PER', 'VIP1', 'VIP2', 'BLV'};
sizes = size (tfs);
n = sizes(2);
prefixes = cell (1, 2^n - 1);
a = 1;
for i = 1:n
    x = strcat(prefix, tfs{i}, '_', suffix);
    prefixes{a} = x;
    a = a + 1;
end
for i = 1:n
    for j = i+1:n
        x = strcat(prefix, tfs{i}, '_', tfs{j}, '_', suffix); 
        prefixes{a} = x;
        a = a + 1;
    end
end
for i = 1:n
    for j = i+1:n
        for k = j+1:n
            x = strcat(prefix, tfs{i}, '_', tfs{j}, '_', tfs{k}, '_', suffix);
            prefixes{a} = x;
            a = a + 1;
        end
    end
end
x = strcat(prefix, tfs{1}, '_', tfs{2}, '_', tfs{3}, '_', tfs{4}, '_', suffix);
prefixes{a} = x;