Write a program to display a piecewise linear approximation of a price path as follows. Let S₀, S₁, S₂, ..., S₃₆₅ be a 1 year sequence of prices. Select a subset of these, for example monthly S₀, S₃₀, ..., S₃₆₄, and generate the piecewise linear graph through these points, (0, S₀), (30, S₃₀), ..., (364, S₃₆₄). Such an approximation could serve as an alternative to the moving average of the prices.