> Ouch…
> Quick workaround: use `x.harden_mask()` *then* `x.mask.flags.writeable=False`
Thanks for the update and the detailed explanation. I'll try this trick.
> This may change in the future, depending on a yet-to-be-achieved consensus on
> the definition of 'least-surprising behaviour'. Rig
On Jul 15, 2013, at 14:40 , Gregorio Bastardo
wrote:
> Hi Pierre,
>
>> Note as well that hardening the mask only prevents unmasking: you can still
>> grow the mask, which may not be what you want. Use
>> `x.mask.flags.writeable=False` to make the mask really read-only.
>
> I ran into an unm
Hi Pierre,
> Note as well that hardening the mask only prevents unmasking: you can still
> grow the mask, which may not be what you want. Use
> `x.mask.flags.writeable=False` to make the mask really read-only.
I ran into an unmasking problem with the suggested approach:
>>> np.version.version
On Jul 15, 2013, at 10:04 , Gregorio Bastardo
wrote:
> Hi Pierre,
>
>> I'm a bit surprised, though. Here's what I tried
>>
> np.version.version
>> <<< 1.7.0
> x = np.ma.array([1,2,3], mask=[0,1,0])
> x.flags.writeable=False
> x[0]=-1
>> <<< ValueError: assignment destination i
Hi Pierre,
> I'm a bit surprised, though. Here's what I tried
>
np.version.version
> <<< 1.7.0
x = np.ma.array([1,2,3], mask=[0,1,0])
x.flags.writeable=False
x[0]=-1
> <<< ValueError: assignment destination is read-only
Thanks, it works perfectly =) Sorry, probably have overlo
On Jul 13, 2013, at 13:36 , Gregorio Bastardo
wrote:
> Hi Stéfan,
>
> Thanks for the suggestion, but it does not protect the array:
Thinking about it, it can't: when `x` is a MaskedArray, `x.data` is just a view
of the underlying array as a regular ndarray. As far as I understand, changing
Hi Stéfan,
Thanks for the suggestion, but it does not protect the array:
>>> x = np.ma.masked_array(xrange(4), [0,1,0,1])
>>> x
masked_array(data = [0 -- 2 --],
mask = [False True False True],
fill_value = 99)
>>> x.mask.flags.writeable = False
>>> x.data.flags.writeable
On Fri, Jul 12, 2013 at 4:41 PM, Gregorio Bastardo
wrote:
> array.flags.writeable = False
>
> is perfectly fine, but it does not work on ma-s. Moreover, mask
> hardening only protects masked elements, and does not raise error (as
> I'd expect).
You probably have to modify the underlying array and
Hi,
I use masked arrays to mark missing values in data and found it very
convenient, although sometimes counterintuitive.
I'd like to make a pool of masked arrays (shared between several
processing steps) read-only (both data and mask property) to protect
the arrays from accidental modification (
