@window_filter(nim, coef:tab, pos:numeric)
build a new nim by processing each component independently.
Each component is the result of a smoothing process of the breakpoints.
Ecah breakpoint of the new nim is computed by the dot product of
with a sequence of
y of the same length as
coef where position
corresponds to the current breakpoint.
@window_filter(nim, , 0)
build a nim by
scaling the image of
nim by 2.
@window_filter(nim, [0.1, 0.2, 0.4, 0.2, 0.1], 2)
is a moving weighted average with
symmetric weights around