diff options
Diffstat (limited to 'doc/neps')
| -rw-r--r-- | doc/neps/c-masked-array.rst | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/doc/neps/c-masked-array.rst b/doc/neps/c-masked-array.rst index d3cb346eb..3c9fad9dd 100644 --- a/doc/neps/c-masked-array.rst +++ b/doc/neps/c-masked-array.rst @@ -120,15 +120,13 @@ from another view which doesn't have them masked. For example:: array([NA,2], masked=True) >>> a array([1,2]) - >>> # The underlying value in 'a' was untouched + >>> # The underlying number 1 value in 'a[0]' was untouched If np.NA or masked values are copied to an array without a mask, an exception will be raised. Adding a validitymask to the target array would be problematic, because then having a mask would be a "viral" property consuming extra memory and reducing performance in unexpected -ways. To assign a value would require a default value, which is -something that should be explicitly stated, so a function like -"a.assign_from_masked(b, maskedvalue=3.0)" needs to be created. +ways. By default, the string "NA" will be used to represent masked values in str and repr outputs. A global default configuration will allow @@ -136,7 +134,7 @@ this to be changed. The array2string function will also gain a 'maskedstr=' parameter so this could be changed to "NA" or other values people may desire. For example,:: - >>>np.array([1.0, 2.0, np.NA, 7.0], masked=True) + >>> np.array([1.0, 2.0, np.NA, 7.0], masked=True) will produce an array with values [1.0, 2.0, <inaccessible>, 7.0], and validitymask [True, True, False, True]. @@ -144,7 +142,9 @@ validitymask [True, True, False, True]. For floating point numbers, Inf and NaN are separate concepts from missing values. If a division by zero occurs, an unmasked Inf or NaN will be produced. To mask those values, a further 'a.validitymask &= np.isfinite(a)' -can achieve that. +can achieve that. If the parameterized dtype('NA[f8,InfNan]') is +implemented as described in a later section, this mechanism could be +used to get these semantics without the extra mask manipulation. A manual loop through a masked array like:: |