Re: [Numpy-discussion] byteswapping a complex scalar

On Oct 7, 2009, at 10:28 AM, Michael Droettboom wrote:

I'm noticing an inconsistency as to how complex numbers are byteswapped as arrays vs. scalars, and wondering if I'm doing something wrong.

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x = np.array([-1j], '

# When I swap the whole array, it swaps each of the (real, imag) parts separately

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y = x.byteswap() y.tostring().encode('hex') '00000000bf800000' # and this round-trips fine z = np.fromstring(y.tostring(), dtype='>c8') assert z[0] == -1j

# When I swap the scalar, it seems to swap the entire 8 bytes

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y = x[0].byteswap() y.tostring().encode('hex') 'bf80000000000000' # ...and this doesn't round-trip z = np.fromstring(y.tostring(), dtype='>c8') assert z[0] == -1j Traceback (most recent call last): File "<stdin>", line 1, in <module> AssertionError

Any thoughts?

I just checked a fix for this into SVN (tests still need to be added though...) I can't currently build SVN on my Mac for some reason (I don't know if it has to do with recent changes or not, but I don't have time to track it down right now....the error I'm getting is something about Datetime array scalar types not being defined which seems related to the work Dave and Stefan have been discussing). It's a small change, though, and should work. -Travis