hdf-0.15: Help/hdf.lhs
# hdf
> import Sound.DF.Uniform.GADT
A counter is a first order `iir` at `+` with a unit delay.
> audition_text 5 (out1 (unit_delay 0.0 (iir1 0.0 (+) 1.0)))
0: 0.000000
1: 1.000000
2: 2.000000
3: 3.000000
4: 4.000000
The graph drawing indicates two backward arcs, one introduced by
`iir1`, the other by `unit_delay`.
> draw (out1 (counter 0.0 1.0))
An alternative drawing can be made that includes the _read_ and
_write_ nodes that implement the recursion scheme, connected by an
_implicit_ edge.
> gr_draw' (out1 (counter 0.0 1.0))
