p = 0.5;
nsteps = 100;
nwalks = 1000;

y = zeros( nwalks, nsteps/10 );
for k = 1:length( y )
    x = randomwalk( nsteps, p );
    for j = 1:nsteps/10
        y(k,j) = x((j-1)*10+1);
    end
    %plot( x )
    %pause( 1 )
    if rem(k,100) == 0
        %[h1,b1] = hist( y(1:k,1), [-50:2:50] );
        %[h2,b2] = hist( y(1:k,2), [-50:2:50] );
        %bar( b1, h1, 1.0, 'b' );
        %hold on;
        %bar( b2, h2, 'FaceColor', 'r' );
        %hold off;
        sdev = var( y(1:k,:), 1 );
        plot( sdev )
        pause( 1.0 );
    end
end