Plotting simple algorithm, problem with axis

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MiauMiau 2013-2-21

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https://ww2.mathworks.cn/matlabcentral/answers/64383-plotting-simple-algorithm-problem-with-axis

Below my algorithm: First I store the so called Lucas Numbers in a vector v. v contains the N first lucasnumbers. Then I calculate the ratio of the two consequent lucas numbers, i.e. w(1) = v(2)/v(1) etc. and store these results in a vector w with length N-1.

What I want to do next then, is to calculate the absolute value between a defined constant phi and the elements of w and plot them as a function of N-1. But when I try to do so, for the x-axis I never get the range 1:N-1. Why is that?

function plotLucas(N)
% initialize vector v
% v contains the Lucas Numbers
v = zeros(N,1)
v(1) = 1;
v(2) = 3;
for i = 3:size(v,1)
    v(i) = v(i-1)+v(i-2)
end
% initialize vector w
% w contains the quotients
w = zeros(N-1,1)
for i = 1:size(w,1)
    w(i) = v(i+1)/v(i);
end
phiLucas = (1+sqrt(5))/2
y = abs(w-phiLucas)
plot(y, 1:N-1)
end