map - linear mapping unit generator

map  output[b] in[bvpn] imin[bvpn] imax[bvpn] omin[bvpn] omax[bvpn] clip[vpn] ;

The input signal is considered to lie in the range [imin, imax].  The
output signal has the same shape as the input mapped into the range
[omin, omax].  The mapping rule is linear, meaning that if the input
signal value lies p% of the way from imin to imax, then the
corresponding output will lie p% of the way from omin to omax according to
the relation

                                             (in-imin)
                output = omin + (omax-omin)* ---------
                                            (imax-imin)

If clip is nonzero, then input signal values are first clipped to the input 
range--if clip is zero, no such clipping is done (note that clip must be a 
constant).
