generate_variation.m

function [res] = generate_variation(fouten_marge, len)

res = -10000 + (10000 - (-10000)) * rand(floor(len), 1);

res(abs(res) < 0.0001) = 1;

all_pos = sum(res > 0) == len;
all_neg = sum(res < 0) == len;
all_small = sum(abs(res) < 1) == len;

if all_pos || all_neg
    res(1) = res(1) * -1;
    res(len) = res(len) * -1;
end

if all_small
    res(1) = 11;
    res(len) = -19;
end

pos_sum = sum(res(res > 0));
neg_sum = sum(res(res < 0));

res(res < 0) = res(res < 0) / abs(neg_sum);
res(res > 0) = res(res > 0) / pos_sum;

[~, max_abs_i] = max(abs(res));
max_abs = res(max_abs_i);

delta = 0.1 + (abs(fouten_marge) - 0.1) * rand;

res = res / abs(max_abs) * delta;

end

generate_variation2.m

function [res] = generate_variation2(fouten_marge, len)

res1 = 10000 - 1000 * rand(len, 1);
res2 = sign(-10000 + (10000 - (-10000)) * rand(len, 1));
res = res1 .* res2;

res(abs(res) < 0.0001) = 1;

all_pos = sum(res > 0) == len;
all_neg = sum(res < 0) == len;
all_small = sum(abs(res) < 1) == len;

if all_pos || all_neg
    res(1) = res(1) * -1;
    res(len) = res(len) * -1;
end

if all_small
    res(1) = 11;
    res(len) = -19;
end

pos_sum = sum(res(res > 0));
neg_sum = sum(res(res < 0));

res(res < 0) = res(res < 0) / abs(neg_sum);
res(res > 0) = res(res > 0) / pos_sum;

[~, max_abs_i] = max(abs(res));
max_abs = res(max_abs_i);

delta = 0.1 + (abs(fouten_marge) - 0.1) * rand;

res = res / abs(max_abs) * delta;

end