On Thu, Feb 12, 2015 at 3:22 PM, Neal Becker <ndbeck...@gmail.com> wrote:
>
> Robert Kern wrote:
>
> > On Thu, Feb 12, 2015 at 3:00 PM, Neal Becker <ndbeck...@gmail.com>
wrote:
> >>
> >> Robert Kern wrote:
> >>
> >> > On Thu, Feb 12, 2015 at 2:21 PM, Neal Becker <ndbeck...@gmail.com>
> > wrote:
> >> >>
> >> >> I need to transmit some data values. These values will be float and
> > long
> >> >> values. I need them encoded into a string of bits.
> >> >>
> >> >> The only way I found so far to do this seems rather roundabout:
> >> >>
> >> >>
> >> >> np.unpackbits (np.array (memoryview(struct.pack ('d', pi))))
> >> >> Out[45]:
> >> >> array([0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0,
0,
> > 1,
> >> > 0,
> >> >> 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 1,
0,
> > 0,
> >> > 0,
> >> >> 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0],
> > dtype=uint8)
> >> >>
> >> >> (which I'm not certain is correct)
> >> >>
> >> >> Also, I don't know how to reverse this process
> >> >
> >> > You already had your string ready for transmission with
> > `struct.pack('d',
> >> > pi)`.
> >> >
> >> > --
> >> > Robert Kern
> >>
> >> my transmitter wants an np array of bits, not a string
> >
> > Can you provide any details on what your "transmitter" is?
> >
> > --
>
> My transmitter is c++ code that accepts as input a numpy array of
np.int32.
> Each element of that array has value 0 or 1.
Ah, great. That makes sense, then.
def tobeckerbits(x):
return np.unpackbits(np.frombuffer(np.asarray(x),
dtype=np.uint8)).astype(np.int32)
def frombeckerbits(bits, dtype):
return np.frombuffer(np.packbits(bits), dtype=dtype)[0]
--
Robert Kern
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