How do I make a function to plot a given number of graphs(from a user input) from 30 columns of data?

So I have a matrix L, which has 30 columns of data. I want to make a function which will be something like composite_plot_tsd(L,y). Where y is the number of graphs I want the 30 columns of data to be plotted on. So far I have this:

function [y] = composite_plot_tsd(L,y)

n=30;

ncols = ceil(30/y); % columns per plot

for i = 1:y

    figure
    kstart = (i-1) * ncols+1;
    kend = min(kstart + ncols-1 ,n);
    for j = kstart:kend
        plot(L(:,j)),hold on
    end
end

So for example if I used the function composite_plot_tsd(L,9), it would plot the 30 columns of data onto 9 separate figures. However the problem with my code is that with a number that isn't divisible by 30 it only plots onto 8 figures. I was hoping someone could help me correct my code and guide me in the right direction.