[Matplotlib-users] Stineman interpolation

[Krishna B. <kri...@gm...>]

Hi,

Given that the values of ordinates are changing monotonically, I found that
in some cases, stineman interpolation is monotonic even when the slopes are
not monotonic. And in other cases, it overshoots. Like in the following one:

x = (0, 10, 70, 100)
y = (0, 535, 595, 1000)
xx = arange(0,100,1)
yy = stineman_interp(xx,x,y,yp=None)
plot(x,y,'x')
plot(xx,yy)

Are there some factors that can make the interpolation monotonic, when the
slopes are not monotonic? or does it depend on case by case basis?