numpy.seterr¶
- numpy.seterr(all=None, divide=None, over=None, under=None, invalid=None)[source]¶
Set how floating-point errors are handled.
Note that operations on integer scalar types (such as int16) are handled like floating point, and are affected by these settings.
Parameters: all : {‘ignore’, ‘warn’, ‘raise’, ‘call’, ‘print’, ‘log’}, optional
Set treatment for all types of floating-point errors at once:
- ignore: Take no action when the exception occurs.
- warn: Print a RuntimeWarning (via the Python warnings module).
- raise: Raise a FloatingPointError.
- call: Call a function specified using the seterrcall function.
- print: Print a warning directly to stdout.
- log: Record error in a Log object specified by seterrcall.
The default is not to change the current behavior.
divide : {‘ignore’, ‘warn’, ‘raise’, ‘call’, ‘print’, ‘log’}, optional
Treatment for division by zero.
over : {‘ignore’, ‘warn’, ‘raise’, ‘call’, ‘print’, ‘log’}, optional
Treatment for floating-point overflow.
under : {‘ignore’, ‘warn’, ‘raise’, ‘call’, ‘print’, ‘log’}, optional
Treatment for floating-point underflow.
invalid : {‘ignore’, ‘warn’, ‘raise’, ‘call’, ‘print’, ‘log’}, optional
Treatment for invalid floating-point operation.
Returns: old_settings : dict
Dictionary containing the old settings.
Notes
The floating-point exceptions are defined in the IEEE 754 standard [1]:
- Division by zero: infinite result obtained from finite numbers.
- Overflow: result too large to be expressed.
- Underflow: result so close to zero that some precision was lost.
- Invalid operation: result is not an expressible number, typically indicates that a NaN was produced.
[R281] http://en.wikipedia.org/wiki/IEEE_754 Examples
>>> old_settings = np.seterr(all='ignore') #seterr to known value >>> np.seterr(over='raise') {'over': 'ignore', 'divide': 'ignore', 'invalid': 'ignore', 'under': 'ignore'} >>> np.seterr(**old_settings) # reset to default {'over': 'raise', 'divide': 'ignore', 'invalid': 'ignore', 'under': 'ignore'}
>>> np.int16(32000) * np.int16(3) 30464 >>> old_settings = np.seterr(all='warn', over='raise') >>> np.int16(32000) * np.int16(3) Traceback (most recent call last): File "<stdin>", line 1, in <module> FloatingPointError: overflow encountered in short_scalars Traceback (most recent call last): File "<stdin>", line 1, in <module> FloatingPointError: overflow encountered in short_scalars
>>> old_settings = np.seterr(all='print') >>> np.geterr() {'over': 'print', 'divide': 'print', 'invalid': 'print', 'under': 'print'} >>> np.int16(32000) * np.int16(3) Warning: overflow encountered in short_scalars 30464