"""Array printing function
$Id: arrayprint.py,v 1.9 2005/09/13 13:58:44 teoliphant Exp $
"""
__all__ = ["array2string", "set_printoptions", "get_printoptions"]
__docformat__ = 'restructuredtext'
#
# Written by Konrad Hinsen <hinsenk@ere.umontreal.ca>
# last revision: 1996-3-13
# modified by Jim Hugunin 1997-3-3 for repr's and str's (and other details)
# and by Perry Greenfield 2000-4-1 for numarray
# and by Travis Oliphant 2005-8-22 for numpy
import sys
import numerictypes as _nt
from umath import maximum,minimum,absolute,not_equal,isnan,isinf
from multiarray import format_longfloat
from fromnumeric import ravel
def product(x, y): return x*y
_summaryEdgeItems = 3 # repr N leading and trailing items of each dimension
_summaryThreshold = 1000 # total items > triggers array summarization
_float_output_precision = 8
_float_output_suppress_small = False
_line_width = 75
_nan_str = 'NaN'
_inf_str = 'Inf'
if sys.version_info[0] >= 3:
from functools import reduce
def set_printoptions(precision=None, threshold=None, edgeitems=None,
linewidth=None, suppress=None,
nanstr=None, infstr=None):
"""
Set printing options.
These options determine the way floating point numbers, arrays and
other NumPy objects are displayed.
Parameters
----------
precision : int, optional
Number of digits of precision for floating point output (default 8).
threshold : int, optional
Total number of array elements which trigger summarization
rather than full repr (default 1000).
edgeitems : int, optional
Number of array items in summary at beginning and end of
each dimension (default 3).
linewidth : int, optional
The number of characters per line for the purpose of inserting
line breaks (default 75).
suppress : bool, optional
Whether or not suppress printing of small floating point values
using scientific notation (default False).
nanstr : str, optional
String representation of floating point not-a-number (default NaN).
infstr : str, optional
String representation of floating point infinity (default Inf).
See Also
--------
get_printoptions, set_string_function
Examples
--------
Floating point precision can be set:
>>> np.set_printoptions(precision=4)
>>> print np.array([1.123456789])
[ 1.1235]
Long arrays can be summarised:
>>> np.set_printoptions(threshold=5)
>>> print np.arange(10)
[0 1 2 ..., 7 8 9]
Small results can be suppressed:
>>> eps = np.finfo(float).eps
>>> x = np.arange(4.)
>>> x**2 - (x + eps)**2
array([ -4.9304e-32, -4.4409e-16, 0.0000e+00, 0.0000e+00])
>>> np.set_printoptions(suppress=True)
>>> x**2 - (x + eps)**2
array([-0., -0., 0., 0.])
To put back the default options, you can use:
>>> np.set_printoptions(edgeitems=3,infstr='Inf',
... linewidth=75, nanstr='NaN', precision=8,
... suppress=False, threshold=1000)
"""
global _summaryThreshold, _summaryEdgeItems, _float_output_precision, \
_line_width, _float_output_suppress_small, _nan_str, _inf_str
if linewidth is not None:
_line_width = linewidth
if threshold is not None:
_summaryThreshold = threshold
if edgeitems is not None:
_summaryEdgeItems = edgeitems
if precision is not None:
_float_output_precision = precision
if suppress is not None:
_float_output_suppress_small = not not suppress
if nanstr is not None:
_nan_str = nanstr
if infstr is not None:
_inf_str = infstr
def get_printoptions():
"""
Return the current print options.
Returns
-------
print_opts : dict
Dictionary of current print options with keys
- precision : int
- threshold : int
- edgeitems : int
- linewidth : int
- suppress : bool
- nanstr : str
- infstr : str
For a full description of these options, see `set_printoptions`.
See Also
--------
set_printoptions, set_string_function
"""
d = dict(precision=_float_output_precision,
threshold=_summaryThreshold,
edgeitems=_summaryEdgeItems,
linewidth=_line_width,
suppress=_float_output_suppress_small,
nanstr=_nan_str,
infstr=_inf_str)
return d
def _leading_trailing(a):
import numeric as _nc
if a.ndim == 1:
if len(a) > 2*_summaryEdgeItems:
b = _nc.concatenate((a[:_summaryEdgeItems],
a[-_summaryEdgeItems:]))
else:
b = a
else:
if len(a) > 2*_summaryEdgeItems:
l = [_leading_trailing(a[i]) for i in range(
min(len(a), _summaryEdgeItems))]
l.extend([_leading_trailing(a[-i]) for i in range(
min(len(a), _summaryEdgeItems),0,-1)])
else:
l = [_leading_trailing(a[i]) for i in range(0, len(a))]
b = _nc.concatenate(tuple(l))
return b
def _boolFormatter(x):
if x: return ' True'
else: return 'False'
def _array2string(a, max_line_width, precision, suppress_small, separator=' ',
prefix=""):
if max_line_width is None:
max_line_width = _line_width
if precision is None:
precision = _float_output_precision
if suppress_small is None:
suppress_small = _float_output_suppress_small
if a.size > _summaryThreshold:
summary_insert = "..., "
data = _leading_trailing(a)
else:
summary_insert = ""
data = ravel(a)
try:
format_function = a._format
except AttributeError:
dtypeobj = a.dtype.type
if issubclass(dtypeobj, _nt.bool_):
# make sure True and False line up.
format_function = _boolFormatter
elif issubclass(dtypeobj, _nt.integer):
if issubclass(dtypeobj, _nt.timeinteger):
format_function = str
else:
max_str_len = max(len(str(maximum.reduce(data))),
len(str(minimum.reduce(data))))
format = '%' + str(max_str_len) + 'd'
format_function = lambda x: _formatInteger(x, format)
elif issubclass(dtypeobj, _nt.floating):
if issubclass(dtypeobj, _nt.longfloat):
format_function = _longfloatFormatter(precision)
else:
format_function = FloatFormat(data, precision, suppress_small)
elif issubclass(dtypeobj, _nt.complexfloating):
if issubclass(dtypeobj, _nt.clongfloat):
format_function = _clongfloatFormatter(precision)
else:
format_function = ComplexFormat(data, precision, suppress_small)
elif issubclass(dtypeobj, _nt.unicode_) or \
issubclass(dtypeobj, _nt.string_):
format_function = repr
else:
format_function = str
next_line_prefix = " " # skip over "["
next_line_prefix += " "*len(prefix) # skip over array(
lst = _formatArray(a, format_function, len(a.shape), max_line_width,
next_line_prefix, separator,
_summaryEdgeItems, summary_insert)[:-1]
return lst
def _convert_arrays(obj):
import numeric as _nc
newtup = []
for k in obj:
if isinstance(k, _nc.ndarray):
k = k.tolist()
elif isinstance(k, tuple):
k = _convert_arrays(k)
newtup.append(k)
return tuple(newtup)
def array2string(a, max_line_width = None, precision = None,
suppress_small = None, separator=' ', prefix="",
style=repr):
"""
Return a string representation of an array.
Parameters
----------
a : ndarray
Input array.
max_line_width : int, optional
The maximum number of columns the string should span. Newline
characters splits the string appropriately after array elements.
precision : int, optional
Floating point precision. Default is the current printing
precision (usually 8), which can be altered using `set_printoptions`.
suppress_small : bool, optional
Represent very small numbers as zero. A number is "very small" if it
is smaller than the current printing precision.
separator : str, optional
Inserted between elements.
prefix : str, optional
An array is typically printed as::
'prefix(' + array2string(a) + ')'
The length of the prefix string is used to align the
output correctly.
style : function, optional
A function that accepts an ndarray and returns a string. Used only
when the shape of `a` is equal to ().
Returns
-------
array_str : str
String representation of the array.
See Also
--------
array_str, array_repr, set_printoptions
Examples
--------
>>> x = np.array([1e-16,1,2,3])
>>> print np.array2string(x, precision=2, separator=',',
... suppress_small=True)
[ 0., 1., 2., 3.]
"""
if a.shape == ():
x = a.item()
try:
lst = a._format(x)
except AttributeError:
if isinstance(x, tuple):
x = _convert_arrays(x)
lst = style(x)
elif reduce(product, a.shape) == 0:
# treat as a null array if any of shape elements == 0
lst = "[]"
else:
lst = _array2string(a, max_line_width, precision, suppress_small,
separator, prefix)
return lst
def _extendLine(s, line, word, max_line_len, next_line_prefix):
if len(line.rstrip()) + len(word.rstrip()) >= max_line_len:
s += line.rstrip() + "\n"
line = next_line_prefix
line += word
return s, line
def _formatArray(a, format_function, rank, max_line_len,
next_line_prefix, separator, edge_items, summary_insert):
"""formatArray is designed for two modes of operation:
1. Full output
2. Summarized output
"""
if rank == 0:
obj = a.item()
if isinstance(obj, tuple):
obj = _convert_arrays(obj)
return str(obj)
if summary_insert and 2*edge_items < len(a):
leading_items, trailing_items, summary_insert1 = \
edge_items, edge_items, summary_insert
else:
leading_items, trailing_items, summary_insert1 = 0, len(a), ""
if rank == 1:
s = ""
line = next_line_prefix
for i in xrange(leading_items):
word = format_function(a[i]) + separator
s, line = _extendLine(s, line, word, max_line_len, next_line_prefix)
if summary_insert1:
s, line = _extendLine(s, line, summary_insert1, max_line_len, next_line_prefix)
for i in xrange(trailing_items, 1, -1):
word = format_function(a[-i]) + separator
s, line = _extendLine(s, line, word, max_line_len, next_line_prefix)
word = format_function(a[-1])
s, line = _extendLine(s, line, word, max_line_len, next_line_prefix)
s += line + "]\n"
s = '[' + s[len(next_line_prefix):]
else:
s = '['
sep = separator.rstrip()
for i in xrange(leading_items):
if i > 0:
s += next_line_prefix
s += _formatArray(a[i], format_function, rank-1, max_line_len,
" " + next_line_prefix, separator, edge_items,
summary_insert)
s = s.rstrip() + sep.rstrip() + '\n'*max(rank-1,1)
if summary_insert1:
s += next_line_prefix + summary_insert1 + "\n"
for i in xrange(trailing_items, 1, -1):
if leading_items or i != trailing_items:
s += next_line_prefix
s += _formatArray(a[-i], format_function, rank-1, max_line_len,
" " + next_line_prefix, separator, edge_items,
summary_insert)
s = s.rstrip() + sep.rstrip() + '\n'*max(rank-1,1)
if leading_items or trailing_items > 1:
s += next_line_prefix
s += _formatArray(a[-1], format_function, rank-1, max_line_len,
" " + next_line_prefix, separator, edge_items,
summary_insert).rstrip()+']\n'
return s
class FloatFormat(object):
def __init__(self, data, precision, suppress_small, sign=False):
self.precision = precision
self.suppress_small = suppress_small
self.sign = sign
self.exp_format = False
self.large_exponent = False
self.max_str_len = 0
self.fillFormat(data)
def fillFormat(self, data):
import numeric as _nc
errstate = _nc.seterr(all='ignore')
try:
special = isnan(data) | isinf(data)
non_zero = absolute(data.compress(not_equal(data, 0) & ~special))
if len(non_zero) == 0:
max_val = 0.
min_val = 0.
else:
max_val = maximum.reduce(non_zero)
min_val = minimum.reduce(non_zero)
if max_val >= 1.e8:
self.exp_format = True
if not self.suppress_small and (min_val < 0.0001
or max_val/min_val > 1000.):
self.exp_format = True
finally:
_nc.seterr(**errstate)
if self.exp_format:
self.large_exponent = 0 < min_val < 1e-99 or max_val >= 1e100
self.max_str_len = 8 + self.precision
if self.large_exponent:
self.max_str_len += 1
if self.sign:
format = '%+'
else:
format = '%'
format = format + '%d.%de' % (self.max_str_len, self.precision)
else:
format = '%%.%df' % (self.precision,)
if len(non_zero):
precision = max([_digits(x, self.precision, format)
for x in non_zero])
else:
precision = 0
precision = min(self.precision, precision)
self.max_str_len = len(str(int(max_val))) + precision + 2
if _nc.any(special):
self.max_str_len = max(self.max_str_len,
len(_nan_str),
len(_inf_str)+1)
if self.sign:
format = '%#+'
else:
format = '%#'
format = format + '%d.%df' % (self.max_str_len, precision)
self.special_fmt = '%%%ds' % (self.max_str_len,)
self.format = format
def __call__(self, x, strip_zeros=True):
import numeric as _nc
err = _nc.seterr(invalid='ignore')
try:
if isnan(x):
return self.special_fmt % (_nan_str,)
elif isinf(x):
if x > 0:
return self.special_fmt % (_inf_str,)
else:
return self.special_fmt % ('-' + _inf_str,)
finally:
_nc.seterr(**err)
s = self.format % x
if self.large_exponent:
# 3-digit exponent
expsign = s[-3]
if expsign == '+' or expsign == '-':
s = s[1:-2] + '0' + s[-2:]
elif self.exp_format:
# 2-digit exponent
if s[-3] == '0':
s = ' ' + s[:-3] + s[-2:]
elif strip_zeros:
z = s.rstrip('0')
s = z + ' '*(len(s)-len(z))
return s
def _digits(x, precision, format):
s = format % x
z = s.rstrip('0')
return precision - len(s) + len(z)
_MAXINT = sys.maxint
_MININT = -sys.maxint-1
def _formatInteger(x, format):
if _MININT < x < _MAXINT:
return format % x
else:
return "%s" % x
def _longfloatFormatter(precision):
# XXX Have to add something to determine the width to use a la FloatFormat
# Right now, things won't line up properly
def formatter(x):
if isnan(x):
return _nan_str
elif isinf(x):
if x > 0:
return _inf_str
else:
return '-' + _inf_str
return format_longfloat(x, precision)
return formatter
def _clongfloatFormatter(precision):
def formatter(x):
r = format_longfloat(x.real, precision)
i = format_longfloat(x.imag, precision)
return '%s+%sj' % (r, i)
return formatter
class ComplexFormat(object):
def __init__(self, x, precision, suppress_small):
self.real_format = FloatFormat(x.real, precision, suppress_small)
self.imag_format = FloatFormat(x.imag, precision, suppress_small,
sign=True)
def __call__(self, x):
r = self.real_format(x.real, strip_zeros=False)
i = self.imag_format(x.imag, strip_zeros=False)
if not self.imag_format.exp_format:
z = i.rstrip('0')
i = z + 'j' + ' '*(len(i)-len(z))
else:
i = i + 'j'
return r + i
## end
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