On 11.10.2011, at 9:18PM, josef.pktd@gmail.com wrote:
In [42]: c = np.zeros(4, np.int16) In [43]: d = np.zeros(4, np.int32) In [44]: np.around([1.6,np.nan,np.inf,-np.inf], out=c) Out[44]: array([2, 0, 0, 0], dtype=int16)
In [45]: np.around([1.6,np.nan,np.inf,-np.inf], out=d) Out[45]: array([ 2, -2147483648, -2147483648, -2147483648], dtype=int32)
Perhaps a starting point to harmonise this behaviour and get it closer to your expectations (it still would not be really nice having to define the output array first, I guess)...
what numpy is this?
This was 1.6.1 I did suppress a RuntimeWarning that was raised on the first call, though: In [33]: np.around([1.67,np.nan,np.inf,-np.inf], decimals=1, out=d) /sw/lib/python2.7/site-packages/numpy/core/fromnumeric.py:37: RuntimeWarning: invalid value encountered in multiply result = getattr(asarray(obj),method)(*args, **kwds)
np.array([1.6, np.nan, np.inf, -np.inf]).astype(np.int16) array([ 1, -32768, -32768, -32768], dtype=int16) np.__version__ '1.5.1' a = np.ones(4, np.int16) a[:]=np.array([1.6, np.nan, np.inf, -np.inf]) a array([ 1, -32768, -32768, -32768], dtype=int16)
I thought we get ValueError to avoid nan to zero bugs
a[2] = np.nan Traceback (most recent call last): File "
", line 1, in <module> a[2] = np.nan ValueError: cannot convert float NaN to integer
On master, an integer out raises a TypeError for any float input - not sure I'd consider that an improvement…
np.__version__ '2.0.0.dev-8f689df' np.around([1.6,-23.42, -13.98, 0.14], out=c) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/Users/derek/lib/python2.7/site-packages/numpy/core/fromnumeric.py", line 2277, in around return _wrapit(a, 'round', decimals, out) File "/Users/derek/lib/python2.7/site-packages/numpy/core/fromnumeric.py", line 37, in _wrapit result = getattr(asarray(obj),method)(*args, **kwds) TypeError: ufunc 'rint' output (typecode 'd') could not be coerced to provided output parameter (typecode 'h') according to the casting rule “same_kind“
I thought the NaN might have been dealt with first, before casting to int, but that doesn't seem to be the case (on master, again):
np.around([1.6,np.nan,np.inf,-np.inf]) array([ 2., nan, inf, -inf]) np.around([1.6,np.nan,np.inf,-np.inf]).astype(np.int16) array([2, 0, 0, 0], dtype=int16) np.around([1.6,np.nan,np.inf,-np.inf]).astype(np.int32) array([ 2, -2147483648, -2147483648, -2147483648], dtype=int32)
Cheers, Derek