How can I draw a value randomly from specified CDF?

I have some observations, and I want to mimick sampling based on these observations. Here I consider a non-parametric model, specifically, I use kernel smoothing to estimate a CDF from the limited observations.Then I draw values at random from the obtained CDF.The following is my code,(the idea is to get randomly a cumulative probability using uniform distribution, and take the inverse of the CDF with respect to the probability value)

    x = [randn(100, 1); rand(100, 1)+4; rand(100, 1)+8];
    [f, xi] = ksdensity(x, 'Function', 'cdf', 'NUmPoints', 300);
    cdf = [xi', f'];
    nbsamp = 100;
    rndval = zeros(nbsamp, 1);
    for i = 1:nbsamp
        p = rand;
       [~, idx] = sort(abs(cdf(:, 2) - p));
       rndval(i, 1) = cdf(idx(1), 1);
    end
    figure(1);
    hist(x, 40)

    figure(2);
    hist(rndval, 40)

As shown in the code, I used a synthetic example to test my procedure, but the result is unsatisfactory, as illustrated by the two figures below (the first is for the simulated observations, and the second figure shows the histogram drawn from estimated CDF):

Is there anyone who knows where the problem is? Thank you in advance.