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SciPy Reference Guide, Release 0.8.dev
errprint()
errprint({flag}) sets the error printing flag for special functions (from the cephesmodule). The output is the
previous state. With errprint(0) no error messages are shown; the default is errprint(1). If no argument is given
the current state of the flag is returned and no change occurs.
class errstate(**kwargs)
Context manager for floating-point error handling.
Using an instance of errstate as a context manager allows statements in that context to execute with a known
error handling behavior. Upon entering the context the error handling is set with seterr and seterrcall, and upon
exiting it is reset to what it was before.
See Also:
Parameters
kwargs : {divide, over, under, invalid}
Keyword arguments. The valid keywords are the possible floating-point exceptions.
Each keyword should have a string value that defines the treatment for the particular
error. Possible values are {‘ignore’, ‘warn’, ‘raise’, ‘call’, ‘print’, ‘log’}.
seterr, geterr, seterrcall, geterrcall
Notes
The with statement was introduced in Python 2.5, and can only be used there by importing it: from
__future__ import with_statement. In earlier Python versions the with statement is not available.
For complete documentation of the types of floating-point exceptions and treatment options, see seterr.
Examples
>>> from __future__ import with_statement # use ’with’ in Python 2.5
>>> olderr = np.seterr(all=’ignore’) # Set error handling to known state.
>>> np.arange(3) / 0.
array([ NaN, Inf, Inf])
>>> with np.errstate(divide=’warn’):
... np.arange(3) / 0.
...
__main__:2: RuntimeWarning: divide by zero encountered in divide
array([ NaN, Inf, Inf])
>>> np.sqrt(-1)
nan
>>> with np.errstate(invalid=’raise’):
... np.sqrt(-1)
...
Traceback (most recent call last):
File "", line 2, in
FloatingPointError: invalid value encountered in sqrt
Outside the context the error handling behavior has not changed:
>>> np.geterr()
{’over’: ’ignore’, ’divide’: ’ignore’, ’invalid’: ’ignore’,
’under’: ’ignore’}
3.17. Special functions (scipy.special) 423