def triu(m, k=0):
""" returns the elements on and above the k-th diagonal of m. k=0 is the
main diagonal, k > 0 is above and k < 0 is below the main diagonal.
"""
m = asanyarray(m)
out = multiply((1-tri(m.shape[0], m.shape[1], k-1, int)),m)
return out
def diff(a, n=1, axis=-1, skip=1):
if n == 0:
return a
if n < 0:
raise ValueError(
"order must be non-negative but got " + repr(n))
a = asanyarray(a)
nd = len(a.shape)
# print 'nd', nd
slice1 = [slice(None)]*nd
# print '1st slice1', slice1
slice2 = [slice(None)]*nd
# print '1st slice2', slice2
slice1[axis] = slice(skip, None)
# print '2nd slice1', slice1
slice2[axis] = slice(None, -skip)
# print '2nd slice2', slice2
slice1 = tuple(slice1)
# print '3rd slice1', slice1
slice2 = tuple(slice2)
# print '3rd slice2', slice2
if n > 1:
# print 'n>1: a[slice1] = ', a[slice1]
# print 'n>1: a[slice2] = ', a[slice2]
# print 'n>1: a[slice1]-a[slice2] = ', a[slice1]-a[slice2]
return diff(a[slice1]-a[slice2], n-1, axis=axis)
else:
# print 'n <= 1: a[slice1] = ', a[slice1]
# print 'n <= 1: a[slice2] = ', a[slice2]
# print 'n <= 1: a[slice1]-a[slice2] = ', a[slice1]-a[slice2]
return a[slice1]-a[slice2]
def log2(x, y=None):
"""
Return the base 2 logarithm of the input array, element-wise.
Parameters
----------
x : array_like
Input array.
y : array_like
Optional output array with the same shape as `x`.
Returns
-------
y : ndarray
The logarithm to the base 2 of `x` element-wise.
NaNs are returned where `x` is negative.
See Also
--------
log, log1p, log10
Examples
--------
>>> np.log2([-1, 2, 4])
array([ NaN, 1., 2.])
"""
x = nx.asanyarray(x)
if y is None:
y = nx.log(x)
else:
nx.log(x, y)
y /= _log2
return y
def triu(m, k=0):
"""
Upper triangle of an array.
Return a copy of a matrix with the elements below the `k`-th diagonal
zeroed.
Please refer to the documentation for `tril` for further details.
See Also
--------
tril : lower triangle of an array
Examples
--------
>>> np.triu([[1,2,3],[4,5,6],[7,8,9],[10,11,12]], -1)
array([[ 1, 2, 3],
[ 4, 5, 6],
[ 0, 8, 9],
[ 0, 0, 12]])
"""
m = asanyarray(m)
mask = tri(*m.shape[-2:], k=k-1, dtype=bool)
return where(mask, zeros(1, m.dtype), m)
def kron(a,b):
"""kronecker product of a and b
Kronecker product of two arrays is block array
[[ a[ 0 ,0]*b, a[ 0 ,1]*b, ... , a[ 0 ,n-1]*b ],
[ ... ... ],
[ a[m-1,0]*b, a[m-1,1]*b, ... , a[m-1,n-1]*b ]]
"""
wrapper = get_array_wrap(a, b)
b = asanyarray(b)
a = array(a,copy=False,subok=True,ndmin=b.ndim)
ndb, nda = b.ndim, a.ndim
if (nda == 0 or ndb == 0):
return _nx.multiply(a,b)
as_ = a.shape
bs = b.shape
if not a.flags.contiguous:
a = reshape(a, as_)
if not b.flags.contiguous:
b = reshape(b, bs)
nd = ndb
if (ndb != nda):
if (ndb > nda):
as_ = (1,)*(ndb-nda) + as_
else:
bs = (1,)*(nda-ndb) + bs
nd = nda
result = outer(a,b).reshape(as_+bs)
axis = nd-1
for _ in xrange(nd):
result = concatenate(result, axis=axis)
if wrapper is not None:
result = wrapper(result)
return result
def imag(val):
"""
Return the imaginary part of the elements of the array.
Parameters
----------
val : array_like
Input array.
Returns
-------
out : ndarray
Output array. If `val` is real, the type of `val` is used for the
output. If `val` has complex elements, the returned type is float.
See Also
--------
real, angle, real_if_close
Examples
--------
>>> a = np.array([1+2j, 3+4j, 5+6j])
>>> a.imag
array([ 2., 4., 6.])
>>> a.imag = np.array([8, 10, 12])
>>> a
array([ 1. +8.j, 3.+10.j, 5.+12.j])
"""
return asanyarray(val).imag
def real(val):
"""
Return the real part of the elements of the array.
Parameters
----------
val : array_like
Input array.
Returns
-------
out : ndarray
Output array. If `val` is real, the type of `val` is used for the
output. If `val` has complex elements, the returned type is float.
See Also
--------
real_if_close, imag, angle
Examples
--------
>>> a = np.array([1+2j, 3+4j, 5+6j])
>>> a.real
array([ 1., 3., 5.])
>>> a.real = 9
>>> a
array([ 9.+2.j, 9.+4.j, 9.+6.j])
>>> a.real = np.array([9, 8, 7])
>>> a
array([ 9.+2.j, 8.+4.j, 7.+6.j])
"""
return asanyarray(val).real
def _mean(a, axis=None, dtype=None, out=None, keepdims=False):
arr = asanyarray(a)
is_float16_result = False
rcount = _count_reduce_items(arr, axis)
# Make this warning show up first
if rcount == 0:
warnings.warn("Mean of empty slice.", RuntimeWarning, stacklevel=2)
# Cast bool, unsigned int, and int to float64 by default
if dtype is None:
if issubclass(arr.dtype.type, (nt.integer, nt.bool_)):
dtype = mu.dtype('f8')
elif issubclass(arr.dtype.type, nt.float16):
dtype = mu.dtype('f4')
is_float16_result = True
ret = umr_sum(arr, axis, dtype, out, keepdims)
if isinstance(ret, mu.ndarray):
ret = um.true_divide(
ret, rcount, out=ret, casting='unsafe', subok=False)
if is_float16_result and out is None:
ret = arr.dtype.type(ret)
elif hasattr(ret, 'dtype'):
if is_float16_result:
ret = arr.dtype.type(ret / rcount)
else:
ret = ret.dtype.type(ret / rcount)
else:
ret = ret / rcount
return ret
def tril(m, k=0):
"""
Lower triangle of an array.
Return a copy of an array with elements above the `k`-th diagonal zeroed.
Parameters
----------
m : array_like, shape (M, N)
Input array.
k : int, optional
Diagonal above which to zero elements. `k = 0` (the default) is the
main diagonal, `k < 0` is below it and `k > 0` is above.
Returns
-------
tril : ndarray, shape (M, N)
Lower triangle of `m`, of same shape and data-type as `m`.
See Also
--------
triu : same thing, only for the upper triangle
Examples
--------
>>> np.tril([[1,2,3],[4,5,6],[7,8,9],[10,11,12]], -1)
array([[ 0, 0, 0],
[ 4, 0, 0],
[ 7, 8, 0],
[10, 11, 12]])
"""
m = asanyarray(m)
out = multiply(tri(m.shape[0], m.shape[1], k=k, dtype=m.dtype),m)
return out
def triu(m, k=0):
"""
Upper triangle of an array.
Return a copy of a matrix with the elements below the `k`-th diagonal
zeroed.
Please refer to the documentation for `tril` for further details.
See Also
--------
tril : lower triangle of an array
Examples
--------
>>> np.triu([[1,2,3],[4,5,6],[7,8,9],[10,11,12]], -1)
array([[ 1, 2, 3],
[ 4, 5, 6],
[ 0, 8, 9],
[ 0, 0, 12]])
"""
m = asanyarray(m)
out = multiply((1 - tri(m.shape[0], m.shape[1], k - 1, dtype=m.dtype)), m)
return out
def tril(m, k=0):
""" returns the elements on and below the k-th diagonal of m. k=0 is the
main diagonal, k > 0 is above and k < 0 is below the main diagonal.
"""
m = asanyarray(m)
out = multiply(tri(m.shape[0], m.shape[1], k=k, dtype=int),m)
return out
def iscomplex(x):
"""
Returns a bool array, where True if input element is complex.
What is tested is whether the input has a non-zero imaginary part, not if
the input type is complex.
Parameters
----------
x : array_like
Input array.
Returns
-------
out : ndarray of bools
Output array.
See Also
--------
isreal
iscomplexobj : Return True if x is a complex type or an array of complex
numbers.
Examples
--------
>>> np.iscomplex([1+1j, 1+0j, 4.5, 3, 2, 2j])
array([ True, False, False, False, False, True])
"""
ax = asanyarray(x)
if issubclass(ax.dtype.type, _nx.complexfloating):
return ax.imag != 0
res = zeros(ax.shape, bool)
return res[()] # convert to scalar if needed
def _var(a, axis=None, dtype=None, out=None, ddof=0, keepdims=False):
arr = asanyarray(a)
rcount = _count_reduce_items(arr, axis)
# Make this warning show up on top.
if ddof >= rcount:
warnings.warn("Degrees of freedom <= 0 for slice", RuntimeWarning,
stacklevel=2)
# Cast bool, unsigned int, and int to float64 by default
if dtype is None and issubclass(arr.dtype.type, (nt.integer, nt.bool_)):
dtype = mu.dtype('f8')
# Compute the mean.
# Note that if dtype is not of inexact type then arraymean will
# not be either.
arrmean = umr_sum(arr, axis, dtype, keepdims=True)
if isinstance(arrmean, mu.ndarray):
arrmean = um.true_divide(
arrmean, rcount, out=arrmean, casting='unsafe', subok=False)
else:
arrmean = arrmean.dtype.type(arrmean / rcount)
# Compute sum of squared deviations from mean
# Note that x may not be inexact and that we need it to be an array,
# not a scalar.
x = asanyarray(arr - arrmean)
if issubclass(arr.dtype.type, (nt.floating, nt.integer)):
x = um.multiply(x, x, out=x)
else:
x = um.multiply(x, um.conjugate(x), out=x).real
ret = umr_sum(x, axis, dtype, out, keepdims)
# Compute degrees of freedom and make sure it is not negative.
rcount = max([rcount - ddof, 0])
# divide by degrees of freedom
if isinstance(ret, mu.ndarray):
ret = um.true_divide(
ret, rcount, out=ret, casting='unsafe', subok=False)
elif hasattr(ret, 'dtype'):
ret = ret.dtype.type(ret / rcount)
else:
ret = ret / rcount
return ret
def flipud(m):
""" returns an array with the columns preserved and rows flipped in
the up/down direction. Works on the first dimension of m.
"""
m = asanyarray(m)
if m.ndim < 1:
raise ValueError, "Input must be >= 1-d."
return m[::-1,...]
def fliplr(m):
""" returns an array m with the rows preserved and columns flipped
in the left/right direction. Works on the first two dimensions of m.
"""
m = asanyarray(m)
if m.ndim < 2:
raise ValueError, "Input must be >= 2-d."
return m[:, ::-1]
def stack(arrays, axis=0):
"""
Join a sequence of arrays along a new axis.
The `axis` parameter specifies the index of the new axis in the dimensions
of the result. For example, if ``axis=0`` it will be the first dimension
and if ``axis=-1`` it will be the last dimension.
.. versionadded:: 1.10.0
Parameters
----------
arrays : sequence of array_like
Each array must have the same shape.
axis : int, optional
The axis in the result array along which the input arrays are stacked.
Returns
-------
stacked : ndarray
The stacked array has one more dimension than the input arrays.
See Also
--------
concatenate : Join a sequence of arrays along an existing axis.
split : Split array into a list of multiple sub-arrays of equal size.
Examples
--------
>>> arrays = [np.random.randn(3, 4) for _ in range(10)]
>>> np.stack(arrays, axis=0).shape
(10, 3, 4)
>>> np.stack(arrays, axis=1).shape
(3, 10, 4)
>>> np.stack(arrays, axis=2).shape
(3, 4, 10)
>>> a = np.array([1, 2, 3])
>>> b = np.array([2, 3, 4])
>>> np.stack((a, b))
array([[1, 2, 3],
[2, 3, 4]])
>>> np.stack((a, b), axis=-1)
array([[1, 2],
[2, 3],
[3, 4]])
"""
arrays = [asanyarray(arr) for arr in arrays]
if not arrays:
raise ValueError('need at least one array to stack')
shapes = set(arr.shape for arr in arrays)
if len(shapes) != 1:
raise ValueError('all input arrays must have the same shape')
result_ndim = arrays[0].ndim + 1
if not -result_ndim <= axis < result_ndim:
msg = 'axis {0} out of bounds [-{1}, {1})'.format(axis, result_ndim)
raise IndexError(msg)
if axis < 0:
axis += result_ndim
sl = (slice(None),) * axis + (_nx.newaxis,)
expanded_arrays = [arr[sl] for arr in arrays]
return _nx.concatenate(expanded_arrays, axis=axis)
def append(arr, values, axis=None):
"""Append to the end of an array along axis (ravel first if None)
"""
arr = asanyarray(arr)
if axis is None:
if arr.ndim != 1:
arr = arr.ravel()
values = ravel(values)
axis = arr.ndim-1
return concatenate((arr, values), axis=axis)
def piecewise(x, condlist, funclist, *args, **kw):
"""Return a piecewise-defined function.
x is the domain
condlist is a list of boolean arrays or a single boolean array
The length of the condition list must be n2 or n2-1 where n2
is the length of the function list. If len(condlist)==n2-1, then
an 'otherwise' condition is formed by |'ing all the conditions
and inverting.
funclist is a list of functions to call of length (n2).
Each function should return an array output for an array input
Each function can take (the same set) of extra arguments and
keyword arguments which are passed in after the function list.
A constant may be used in funclist for a function that returns a
constant (e.g. val and lambda x: val are equivalent in a funclist).
The output is the same shape and type as x and is found by
calling the functions on the appropriate portions of x.
Note: This is similar to choose or select, except
the the functions are only evaluated on elements of x
that satisfy the corresponding condition.
The result is
|--
| f1(x) for condition1
y = --| f2(x) for condition2
| ...
| fn(x) for conditionn
|--
"""
x = asanyarray(x)
n2 = len(funclist)
if not isinstance(condlist, type([])):
condlist = [condlist]
n = len(condlist)
if n == n2-1: # compute the "otherwise" condition.
totlist = condlist[0]
for k in range(1, n):
totlist |= condlist[k]
condlist.append(~totlist)
n += 1
if (n != n2):
raise ValueError, "function list and condition list must be the same"
y = empty(x.shape, x.dtype)
for k in range(n):
item = funclist[k]
if not callable(item):
y[condlist[k]] = item
else:
y[condlist[k]] = item(x[condlist[k]], *args, **kw)
return y
def iscomplex(x):
"""Return a boolean array where elements are True if that element
is complex (has non-zero imaginary part).
For scalars, return a boolean.
"""
ax = asanyarray(x)
if issubclass(ax.dtype.type, _nx.complexfloating):
return ax.imag != 0
res = zeros(ax.shape, bool)
return +res # convet to array-scalar if needed
def real_if_close(a, tol=100):
"""
If complex input returns a real array if complex parts are close to zero.
"Close to zero" is defined as `tol` * (machine epsilon of the type for
`a`).
Parameters
----------
a : array_like
Input array.
tol : float
Tolerance in machine epsilons for the complex part of the elements
in the array.
Returns
-------
out : ndarray
If `a` is real, the type of `a` is used for the output. If `a`
has complex elements, the returned type is float.
See Also
--------
real, imag, angle
Notes
-----
Machine epsilon varies from machine to machine and between data types
but Python floats on most platforms have a machine epsilon equal to
2.2204460492503131e-16. You can use 'np.finfo(np.float).eps' to print
out the machine epsilon for floats.
Examples
--------
>>> np.finfo(np.float).eps
2.2204460492503131e-16
>>> np.real_if_close([2.1 + 4e-14j], tol=1000)
array([ 2.1])
>>> np.real_if_close([2.1 + 4e-13j], tol=1000)
array([ 2.1 +4.00000000e-13j])
"""
a = asanyarray(a)
if not issubclass(a.dtype.type, _nx.complexfloating):
return a
if tol > 1:
from numpy.core import getlimits
f = getlimits.finfo(a.dtype.type)
tol = f.eps * tol
if _nx.allclose(a.imag, 0, atol=tol):
a = a.real
return a
def fix(x, y=None):
"""
Round to nearest integer towards zero.
Round an array of floats element-wise to nearest integer towards zero.
The rounded values are returned as floats.
Parameters
----------
x : array_like
An array of floats to be rounded
y : ndarray, optional
Output array
Returns
-------
out : ndarray of floats
The array of rounded numbers
See Also
--------
trunc, floor, ceil
around : Round to given number of decimals
Examples
--------
>>> np.fix(3.14)
3.0
>>> np.fix(3)
3.0
>>> np.fix([2.1, 2.9, -2.1, -2.9])
array([ 2., 2., -2., -2.])
"""
x = nx.asanyarray(x)
y1 = nx.floor(x)
y2 = nx.ceil(x)
if y is None:
y = nx.asanyarray(y1)
y[...] = nx.where(x >= 0, y1, y2)
return y
def log2(x, y=None):
"""Returns the base 2 logarithm of x
If y is an array, the result replaces the contents of y.
"""
x = asanyarray(x)
if y is None:
y = umath.log(x)
else:
umath.log(x, y)
y /= _log2
return y
def flipud(m):
"""
Flip array in the up/down direction.
Flip the entries in each column in the up/down direction.
Rows are preserved, but appear in a different order than before.
Parameters
----------
m : array_like
Input array.
Returns
-------
out : array_like
A view of `m` with the rows reversed. Since a view is
returned, this operation is :math:`\\mathcal O(1)`.
See Also
--------
fliplr : Flip array in the left/right direction.
rot90 : Rotate array counterclockwise.
Notes
-----
Equivalent to ``A[::-1,...]``.
Does not require the array to be two-dimensional.
Examples
--------
>>> A = np.diag([1.0, 2, 3])
>>> A
array([[ 1., 0., 0.],
[ 0., 2., 0.],
[ 0., 0., 3.]])
>>> np.flipud(A)
array([[ 0., 0., 3.],
[ 0., 2., 0.],
[ 1., 0., 0.]])
>>> A = np.random.randn(2,3,5)
>>> np.all(np.flipud(A)==A[::-1,...])
True
>>> np.flipud([1,2])
array([2, 1])
"""
m = asanyarray(m)
if m.ndim < 1:
raise ValueError("Input must be >= 1-d.")
return m[::-1,...]
def rot90(m, k=1):
""" returns the array found by rotating m by k*90
degrees in the counterclockwise direction. Works on the first two
dimensions of m.
"""
m = asanyarray(m)
if m.ndim < 2:
raise ValueError, "Input must >= 2-d."
k = k % 4
if k == 0: return m
elif k == 1: return fliplr(m).swapaxes(0,1)
elif k == 2: return fliplr(flipud(m))
else: return fliplr(m.swapaxes(0,1)) # k==3
def rot90(m, k=1):
"""
Rotate an array by 90 degrees in the counter-clockwise direction.
The first two dimensions are rotated; therefore, the array must be at
least 2-D.
Parameters
----------
m : array_like
Array of two or more dimensions.
k : integer
Number of times the array is rotated by 90 degrees.
Returns
-------
y : ndarray
Rotated array.
See Also
--------
fliplr : Flip an array horizontally.
flipud : Flip an array vertically.
Examples
--------
>>> m = np.array([[1,2],[3,4]], int)
>>> m
array([[1, 2],
[3, 4]])
>>> np.rot90(m)
array([[2, 4],
[1, 3]])
>>> np.rot90(m, 2)
array([[4, 3],
[2, 1]])
"""
m = asanyarray(m)
if m.ndim < 2:
raise ValueError("Input must >= 2-d.")
k = k % 4
if k == 0:
return m
elif k == 1:
return fliplr(m).swapaxes(0,1)
elif k == 2:
return fliplr(flipud(m))
else:
# k == 3
return fliplr(m.swapaxes(0,1))
def predict_from_smiles_conformal_median(regressor_list, smiles):
"""
Description - Predict value of penetration (kp) from a SMILES-description'
of a molecule using the median of multiple conformal models.
"""
print('########## Predict using multiple conformal models ##############')
print smiles
descriptors_df = calculate_descriptors(smiles)
Xvalues = []
Xvalues = asanyarray(descriptors_df.iloc[:,1:])
print(len(Xvalues))
A = pandas.DataFrame(index = range(len(Xvalues)))
B = pandas.DataFrame(index = range(len(Xvalues)))
C = pandas.DataFrame(index = range(len(Xvalues)))
index = list(xrange(len(smiles)))
i = 0
for regressor in regressor_list:
predicted_skin_permiabillity = regressor.predict(Xvalues, significance = 0.2)
predicted_values = pandas.DataFrame(predicted_skin_permiabillity)
A[i] = predicted_values[0]
B[i] = predicted_values[1]
i +=1
#print(predicted_values) DEBUG
C['median_prediction_0'] = A.median(axis=1)
C['median_prediction_1'] = B.median(axis=1)
C['median_prediction'] = (C['median_prediction_0'] + C['median_prediction_1'])/2
C['median_prediction_size'] = C['median_prediction'] - C['median_prediction_0']
#Y_pred_median_test = C['median_prediction'].dropna()
#median_prediction_size = C['median_prediction_size'].dropna().tolist()
if args.verbose:
print('Number of conformal models used: '+ str(i))
print('Predicted range (first entry): '+str(C['median_prediction_0'][0])+' to '+str(C['median_prediction_1'][0]))
print('Predicted value (first entry): '+str(C['median_prediction'][0]))
print('Predicted range (first entry): '+str(C['median_prediction_size'][0]))
#print('Predicted range (second entry): '+str(C['median_prediction_0'][1])+' - '+str(C['median_prediction_1'][1]))
return C
def fix(x, y=None):
""" Round x to nearest integer towards zero.
"""
x = asanyarray(x)
if y is None:
y = nx.floor(x)
else:
nx.floor(x, y)
if x.ndim == 0:
if (x<0):
y += 1
else:
y[x<0] = y[x<0]+1
return y
def fliplr(m):
"""
Flip array in the left/right direction.
Flip the entries in each row in the left/right direction.
Columns are preserved, but appear in a different order than before.
Parameters
----------
m : array_like
Input array.
Returns
-------
f : ndarray
A view of `m` with the columns reversed. Since a view
is returned, this operation is :math:`\\mathcal O(1)`.
See Also
--------
flipud : Flip array in the up/down direction.
rot90 : Rotate array counterclockwise.
Notes
-----
Equivalent to A[:,::-1]. Does not require the array to be
two-dimensional.
Examples
--------
>>> A = np.diag([1.,2.,3.])
>>> A
array([[ 1., 0., 0.],
[ 0., 2., 0.],
[ 0., 0., 3.]])
>>> np.fliplr(A)
array([[ 0., 0., 1.],
[ 0., 2., 0.],
[ 3., 0., 0.]])
>>> A = np.random.randn(2,3,5)
>>> np.all(numpy.fliplr(A)==A[:,::-1,...])
True
"""
m = asanyarray(m)
if m.ndim < 2:
raise ValueError, "Input must be >= 2-d."
return m[:, ::-1]
def imag(val):
"""
Return the imaginary part of array.
Parameters
----------
val : array_like
Input array.
Returns
-------
out : ndarray, real or int
Real part of each element, same shape as `val`.
"""
return asanyarray(val).imag
def real_if_close(a,tol=100):
"""If a is a complex array, return it as a real array if the imaginary
part is close enough to zero.
"Close enough" is defined as tol*(machine epsilon of a's element type).
"""
a = asanyarray(a)
if not issubclass(a.dtype.type, _nx.complexfloating):
return a
if tol > 1:
import getlimits
f = getlimits.finfo(a.dtype.type)
tol = f.eps * tol
if _nx.allclose(a.imag, 0, atol=tol):
a = a.real
return a
def diag(v, k=0):
"""
Extract a diagonal or construct a diagonal array.
See the more detailed documentation for ``numpy.diagonal`` if you use this
function to extract a diagonal and wish to write to the resulting array;
whether it returns a copy or a view depends on what version of numpy you
are using.
Parameters
----------
v : array_like
If `v` is a 2-D array, return a copy of its `k`-th diagonal.
If `v` is a 1-D array, return a 2-D array with `v` on the `k`-th
diagonal.
k : int, optional
Diagonal in question. The default is 0. Use `k>0` for diagonals
above the main diagonal, and `k<0` for diagonals below the main
diagonal.
Returns
-------
out : ndarray
The extracted diagonal or constructed diagonal array.
See Also
--------
diagonal : Return specified diagonals.
diagflat : Create a 2-D array with the flattened input as a diagonal.
trace : Sum along diagonals.
triu : Upper triangle of an array.
tril : Lower triangle of an array.
Examples
--------
>>> x = np.arange(9).reshape((3,3))
>>> x
array([[0, 1, 2],
[3, 4, 5],
[6, 7, 8]])
>>> np.diag(x)
array([0, 4, 8])
>>> np.diag(x, k=1)
array([1, 5])
>>> np.diag(x, k=-1)
array([3, 7])
>>> np.diag(np.diag(x))
array([[0, 0, 0],
[0, 4, 0],
[0, 0, 8]])
"""
v = asanyarray(v)
s = v.shape
if len(s) == 1:
n = s[0]+abs(k)
res = zeros((n, n), v.dtype)
if k >= 0:
i = k
else:
i = (-k) * n
res[:n-k].flat[i::n+1] = v
return res
elif len(s) == 2:
return diagonal(v, k)
else:
raise ValueError("Input must be 1- or 2-d.")
def kron(a, b):
"""
Kronecker product of two arrays.
Computes the Kronecker product, a composite array made of blocks of the
second array scaled by the first.
Parameters
----------
a, b : array_like
Returns
-------
out : ndarray
See Also
--------
outer : The outer product
Notes
-----
The function assumes that the number of dimensions of `a` and `b`
are the same, if necessary prepending the smallest with ones.
If `a.shape = (r0,r1,..,rN)` and `b.shape = (s0,s1,...,sN)`,
the Kronecker product has shape `(r0*s0, r1*s1, ..., rN*SN)`.
The elements are products of elements from `a` and `b`, organized
explicitly by::
kron(a,b)[k0,k1,...,kN] = a[i0,i1,...,iN] * b[j0,j1,...,jN]
where::
kt = it * st + jt, t = 0,...,N
In the common 2-D case (N=1), the block structure can be visualized::
[[ a[0,0]*b, a[0,1]*b, ... , a[0,-1]*b ],
[ ... ... ],
[ a[-1,0]*b, a[-1,1]*b, ... , a[-1,-1]*b ]]
Examples
--------
>>> np.kron([1,10,100], [5,6,7])
array([ 5, 6, 7, 50, 60, 70, 500, 600, 700])
>>> np.kron([5,6,7], [1,10,100])
array([ 5, 50, 500, 6, 60, 600, 7, 70, 700])
>>> np.kron(np.eye(2), np.ones((2,2)))
array([[ 1., 1., 0., 0.],
[ 1., 1., 0., 0.],
[ 0., 0., 1., 1.],
[ 0., 0., 1., 1.]])
>>> a = np.arange(100).reshape((2,5,2,5))
>>> b = np.arange(24).reshape((2,3,4))
>>> c = np.kron(a,b)
>>> c.shape
(2, 10, 6, 20)
>>> I = (1,3,0,2)
>>> J = (0,2,1)
>>> J1 = (0,) + J # extend to ndim=4
>>> S1 = (1,) + b.shape
>>> K = tuple(np.array(I) * np.array(S1) + np.array(J1))
>>> c[K] == a[I]*b[J]
True
"""
b = asanyarray(b)
a = array(a, copy=False, subok=True, ndmin=b.ndim)
ndb, nda = b.ndim, a.ndim
if (nda == 0 or ndb == 0):
return _nx.multiply(a, b)
as_ = a.shape
bs = b.shape
if not a.flags.contiguous:
a = reshape(a, as_)
if not b.flags.contiguous:
b = reshape(b, bs)
nd = ndb
if (ndb != nda):
if (ndb > nda):
as_ = (1,)*(ndb-nda) + as_
else:
bs = (1,)*(nda-ndb) + bs
nd = nda
result = outer(a, b).reshape(as_+bs)
axis = nd-1
for _ in range(nd):
result = concatenate(result, axis=axis)
wrapper = get_array_prepare(a, b)
if wrapper is not None:
result = wrapper(result)
wrapper = get_array_wrap(a, b)
if wrapper is not None:
result = wrapper(result)
return result
def expand_dims(a, axis):
"""
Expand the shape of an array.
Insert a new axis that will appear at the `axis` position in the expanded
array shape.
.. note:: Previous to NumPy 1.13.0, neither ``axis < -a.ndim - 1`` nor
``axis > a.ndim`` raised errors or put the new axis where documented.
Those axis values are now deprecated and will raise an AxisError in the
future.
Parameters
----------
a : array_like
Input array.
axis : int
Position in the expanded axes where the new axis is placed.
Returns
-------
res : ndarray
Output array. The number of dimensions is one greater than that of
the input array.
See Also
--------
squeeze : The inverse operation, removing singleton dimensions
reshape : Insert, remove, and combine dimensions, and resize existing ones
doc.indexing, atleast_1d, atleast_2d, atleast_3d
Examples
--------
>>> x = np.array([1,2])
>>> x.shape
(2,)
The following is equivalent to ``x[np.newaxis,:]`` or ``x[np.newaxis]``:
>>> y = np.expand_dims(x, axis=0)
>>> y
array([[1, 2]])
>>> y.shape
(1, 2)
>>> y = np.expand_dims(x, axis=1) # Equivalent to x[:,np.newaxis]
>>> y
array([[1],
[2]])
>>> y.shape
(2, 1)
Note that some examples may use ``None`` instead of ``np.newaxis``. These
are the same objects:
>>> np.newaxis is None
True
"""
if isinstance(a, matrix):
a = asarray(a)
else:
a = asanyarray(a)
shape = a.shape
if axis > a.ndim or axis < -a.ndim - 1:
# 2017-05-17, 1.13.0
warnings.warn(
"Both axis > a.ndim and axis < -a.ndim - 1 are "
"deprecated and will raise an AxisError in the future.",
DeprecationWarning,
stacklevel=2,
)
# When the deprecation period expires, delete this if block,
if axis < 0:
axis = axis + a.ndim + 1
# and uncomment the following line.
# axis = normalize_axis_index(axis, a.ndim + 1)
return a.reshape(shape[:axis] + (1,) + shape[axis:])
def real(val):
"""Return the real part of val.
Useful if val maybe a scalar or an array.
"""
return asanyarray(val).real
def matrix_power(M, n):
"""
Raise a square matrix to the (integer) power `n`.
For positive integers `n`, the power is computed by repeated matrix
squarings and matrix multiplications. If ``n == 0``, the identity matrix
of the same shape as M is returned. If ``n < 0``, the inverse
is computed and then raised to the ``abs(n)``.
Parameters
----------
M : ndarray or matrix object
Matrix to be "powered." Must be square, i.e. ``M.shape == (m, m)``,
with `m` a positive integer.
n : int
The exponent can be any integer or long integer, positive,
negative, or zero.
Returns
-------
M**n : ndarray or matrix object
The return value is the same shape and type as `M`;
if the exponent is positive or zero then the type of the
elements is the same as those of `M`. If the exponent is
negative the elements are floating-point.
Raises
------
LinAlgError
If the matrix is not numerically invertible.
See Also
--------
matrix
Provides an equivalent function as the exponentiation operator
(``**``, not ``^``).
Examples
--------
>>> from numpy import linalg as LA
>>> i = np.array([[0, 1], [-1, 0]]) # matrix equiv. of the imaginary unit
>>> LA.matrix_power(i, 3) # should = -i
array([[ 0, -1],
[ 1, 0]])
>>> LA.matrix_power(np.matrix(i), 3) # matrix arg returns matrix
matrix([[ 0, -1],
[ 1, 0]])
>>> LA.matrix_power(i, 0)
array([[1, 0],
[0, 1]])
>>> LA.matrix_power(i, -3) # should = 1/(-i) = i, but w/ f.p. elements
array([[ 0., 1.],
[-1., 0.]])
Somewhat more sophisticated example
>>> q = np.zeros((4, 4))
>>> q[0:2, 0:2] = -i
>>> q[2:4, 2:4] = i
>>> q # one of the three quarternion units not equal to 1
array([[ 0., -1., 0., 0.],
[ 1., 0., 0., 0.],
[ 0., 0., 0., 1.],
[ 0., 0., -1., 0.]])
>>> LA.matrix_power(q, 2) # = -np.eye(4)
array([[-1., 0., 0., 0.],
[ 0., -1., 0., 0.],
[ 0., 0., -1., 0.],
[ 0., 0., 0., -1.]])
"""
M = asanyarray(M)
if len(M.shape) != 2 or M.shape[0] != M.shape[1]:
raise ValueError("input must be a square array")
if not issubdtype(type(n), int):
raise TypeError("exponent must be an integer")
from numpy.linalg import inv
if n == 0:
M = M.copy()
M[:] = identity(M.shape[0])
return M
elif n < 0:
M = inv(M)
n *= -1
result = M
if n <= 3:
for _ in range(n - 1):
result = N.dot(result, M)
return result
# binary decomposition to reduce the number of Matrix
# multiplications for n > 3.
beta = binary_repr(n)
Z, q, t = M, 0, len(beta)
while beta[t - q - 1] == '0':
Z = N.dot(Z, Z)
q += 1
result = Z
for k in range(q + 1, t):
Z = N.dot(Z, Z)
if beta[t - k - 1] == '1':
result = N.dot(result, Z)
return result
def imag(val):
"""Return the imaginary part of val.
Useful if val maybe a scalar or an array.
"""
return asanyarray(val).imag
def _parse_einsum_input(operands):
"""
A reproduction of einsum c side einsum parsing in python.
Returns
-------
input_strings : str
Parsed input strings
output_string : str
Parsed output string
operands : list of array_like
The operands to use in the numpy contraction
Examples
--------
The operand list is simplified to reduce printing:
>>> a = np.random.rand(4, 4)
>>> b = np.random.rand(4, 4, 4)
>>> __parse_einsum_input(('...a,...a->...', a, b))
('za,xza', 'xz', [a, b])
>>> __parse_einsum_input((a, [Ellipsis, 0], b, [Ellipsis, 0]))
('za,xza', 'xz', [a, b])
"""
if len(operands) == 0:
raise ValueError("No input operands")
if isinstance(operands[0], str):
subscripts = operands[0].replace(" ", "")
operands = [asanyarray(v) for v in operands[1:]]
# Ensure all characters are valid
for s in subscripts:
if s in '.,->':
continue
if s not in einsum_symbols:
raise ValueError("Character %s is not a valid symbol." % s)
else:
tmp_operands = list(operands)
operand_list = []
subscript_list = []
for p in range(len(operands) // 2):
operand_list.append(tmp_operands.pop(0))
subscript_list.append(tmp_operands.pop(0))
output_list = tmp_operands[-1] if len(tmp_operands) else None
operands = [asanyarray(v) for v in operand_list]
subscripts = ""
last = len(subscript_list) - 1
for num, sub in enumerate(subscript_list):
for s in sub:
if s is Ellipsis:
subscripts += "..."
elif isinstance(s, int):
subscripts += einsum_symbols[s]
else:
raise TypeError("For this input type lists must contain "
"either int or Ellipsis")
if num != last:
subscripts += ","
if output_list is not None:
subscripts += "->"
for s in output_list:
if s is Ellipsis:
subscripts += "..."
elif isinstance(s, int):
subscripts += einsum_symbols[s]
else:
raise TypeError("For this input type lists must contain "
"either int or Ellipsis")
# Check for proper "->"
if ("-" in subscripts) or (">" in subscripts):
invalid = (subscripts.count("-") > 1) or (subscripts.count(">") > 1)
if invalid or (subscripts.count("->") != 1):
raise ValueError("Subscripts can only contain one '->'.")
# Parse ellipses
if "." in subscripts:
used = subscripts.replace(".", "").replace(",", "").replace("->", "")
unused = list(einsum_symbols_set - set(used))
ellipse_inds = "".join(unused)
longest = 0
if "->" in subscripts:
input_tmp, output_sub = subscripts.split("->")
split_subscripts = input_tmp.split(",")
out_sub = True
else:
split_subscripts = subscripts.split(',')
out_sub = False
for num, sub in enumerate(split_subscripts):
if "." in sub:
if (sub.count(".") != 3) or (sub.count("...") != 1):
raise ValueError("Invalid Ellipses.")
# Take into account numerical values
if operands[num].shape == ():
ellipse_count = 0
else:
ellipse_count = max(operands[num].ndim, 1)
ellipse_count -= (len(sub) - 3)
if ellipse_count > longest:
longest = ellipse_count
if ellipse_count < 0:
raise ValueError("Ellipses lengths do not match.")
elif ellipse_count == 0:
split_subscripts[num] = sub.replace('...', '')
else:
rep_inds = ellipse_inds[-ellipse_count:]
split_subscripts[num] = sub.replace('...', rep_inds)
subscripts = ",".join(split_subscripts)
if longest == 0:
out_ellipse = ""
else:
out_ellipse = ellipse_inds[-longest:]
if out_sub:
subscripts += "->" + output_sub.replace("...", out_ellipse)
else:
# Special care for outputless ellipses
output_subscript = ""
tmp_subscripts = subscripts.replace(",", "")
for s in sorted(set(tmp_subscripts)):
if s not in (einsum_symbols):
raise ValueError("Character %s is not a valid symbol." % s)
if tmp_subscripts.count(s) == 1:
output_subscript += s
normal_inds = ''.join(
sorted(set(output_subscript) - set(out_ellipse)))
subscripts += "->" + out_ellipse + normal_inds
# Build output string if does not exist
if "->" in subscripts:
input_subscripts, output_subscript = subscripts.split("->")
else:
input_subscripts = subscripts
# Build output subscripts
tmp_subscripts = subscripts.replace(",", "")
output_subscript = ""
for s in sorted(set(tmp_subscripts)):
if s not in einsum_symbols:
raise ValueError("Character %s is not a valid symbol." % s)
if tmp_subscripts.count(s) == 1:
output_subscript += s
# Make sure output subscripts are in the input
for char in output_subscript:
if char not in input_subscripts:
raise ValueError(
"Output character %s did not appear in the input" % char)
# Make sure number operands is equivalent to the number of terms
if len(input_subscripts.split(',')) != len(operands):
raise ValueError("Number of einsum subscripts must be equal to the "
"number of operands.")
return (input_subscripts, output_subscript, operands)
def polyval(p, x):
"""
Evaluate a polynomial at specific values.
If `p` is of length N, this function returns the value:
``p[0]*x**(N-1) + p[1]*x**(N-2) + ... + p[N-2]*x + p[N-1]``
If `x` is a sequence, then `p(x)` is returned for each element of `x`.
If `x` is another polynomial then the composite polynomial `p(x(t))`
is returned.
Parameters
----------
p : array_like or poly1d object
1D array of polynomial coefficients (including coefficients equal
to zero) from highest degree to the constant term, or an
instance of poly1d.
x : array_like or poly1d object
A number, an array of numbers, or an instance of poly1d, at
which to evaluate `p`.
Returns
-------
values : ndarray or poly1d
If `x` is a poly1d instance, the result is the composition of the two
polynomials, i.e., `x` is "substituted" in `p` and the simplified
result is returned. In addition, the type of `x` - array_like or
poly1d - governs the type of the output: `x` array_like => `values`
array_like, `x` a poly1d object => `values` is also.
See Also
--------
poly1d: A polynomial class.
Notes
-----
Horner's scheme [1]_ is used to evaluate the polynomial. Even so,
for polynomials of high degree the values may be inaccurate due to
rounding errors. Use carefully.
If `x` is a subtype of `ndarray` the return value will be of the same type.
References
----------
.. [1] I. N. Bronshtein, K. A. Semendyayev, and K. A. Hirsch (Eng.
trans. Ed.), *Handbook of Mathematics*, New York, Van Nostrand
Reinhold Co., 1985, pg. 720.
Examples
--------
>>> np.polyval([3,0,1], 5) # 3 * 5**2 + 0 * 5**1 + 1
76
>>> np.polyval([3,0,1], np.poly1d(5))
poly1d([76.])
>>> np.polyval(np.poly1d([3,0,1]), 5)
76
>>> np.polyval(np.poly1d([3,0,1]), np.poly1d(5))
poly1d([76.])
"""
p = NX.asarray(p)
if isinstance(x, poly1d):
y = 0
else:
x = NX.asanyarray(x)
y = NX.zeros_like(x)
for i in range(len(p)):
y = y * x + p[i]
return y
def apply_along_axis(func1d, axis, arr, *args, **kwargs):
"""
Apply a function to 1-D slices along the given axis.
Execute `func1d(a, *args)` where `func1d` operates on 1-D arrays and `a`
is a 1-D slice of `arr` along `axis`.
This is equivalent to (but faster than) the following use of `ndindex` and
`s_`, which sets each of ``ii``, ``jj``, and ``kk`` to a tuple of indices::
Ni, Nk = a.shape[:axis], a.shape[axis+1:]
for ii in ndindex(Ni):
for kk in ndindex(Nk):
f = func1d(arr[ii + s_[:,] + kk])
Nj = f.shape
for jj in ndindex(Nj):
out[ii + jj + kk] = f[jj]
Equivalently, eliminating the inner loop, this can be expressed as::
Ni, Nk = a.shape[:axis], a.shape[axis+1:]
for ii in ndindex(Ni):
for kk in ndindex(Nk):
out[ii + s_[...,] + kk] = func1d(arr[ii + s_[:,] + kk])
Parameters
----------
func1d : function (M,) -> (Nj...)
This function should accept 1-D arrays. It is applied to 1-D
slices of `arr` along the specified axis.
axis : integer
Axis along which `arr` is sliced.
arr : ndarray (Ni..., M, Nk...)
Input array.
args : any
Additional arguments to `func1d`.
kwargs : any
Additional named arguments to `func1d`.
.. versionadded:: 1.9.0
Returns
-------
out : ndarray (Ni..., Nj..., Nk...)
The output array. The shape of `out` is identical to the shape of
`arr`, except along the `axis` dimension. This axis is removed, and
replaced with new dimensions equal to the shape of the return value
of `func1d`. So if `func1d` returns a scalar `out` will have one
fewer dimensions than `arr`.
See Also
--------
apply_over_axes : Apply a function repeatedly over multiple axes.
Examples
--------
>>> def my_func(a):
... \"\"\"Average first and last element of a 1-D array\"\"\"
... return (a[0] + a[-1]) * 0.5
>>> b = np.array([[1,2,3], [4,5,6], [7,8,9]])
>>> np.apply_along_axis(my_func, 0, b)
array([ 4., 5., 6.])
>>> np.apply_along_axis(my_func, 1, b)
array([ 2., 5., 8.])
For a function that returns a 1D array, the number of dimensions in
`outarr` is the same as `arr`.
>>> b = np.array([[8,1,7], [4,3,9], [5,2,6]])
>>> np.apply_along_axis(sorted, 1, b)
array([[1, 7, 8],
[3, 4, 9],
[2, 5, 6]])
For a function that returns a higher dimensional array, those dimensions
are inserted in place of the `axis` dimension.
>>> b = np.array([[1,2,3], [4,5,6], [7,8,9]])
>>> np.apply_along_axis(np.diag, -1, b)
array([[[1, 0, 0],
[0, 2, 0],
[0, 0, 3]],
[[4, 0, 0],
[0, 5, 0],
[0, 0, 6]],
[[7, 0, 0],
[0, 8, 0],
[0, 0, 9]]])
"""
# handle negative axes
arr = asanyarray(arr)
nd = arr.ndim
axis = normalize_axis_index(axis, nd)
# arr, with the iteration axis at the end
in_dims = list(range(nd))
inarr_view = transpose(arr, in_dims[:axis] + in_dims[axis + 1 :] + [axis])
# compute indices for the iteration axes, and append a trailing ellipsis to
# prevent 0d arrays decaying to scalars, which fixes gh-8642
inds = ndindex(inarr_view.shape[:-1])
inds = (ind + (Ellipsis,) for ind in inds)
# invoke the function on the first item
try:
ind0 = next(inds)
except StopIteration:
raise ValueError("Cannot apply_along_axis when any iteration dimensions are 0")
res = asanyarray(func1d(inarr_view[ind0], *args, **kwargs))
# build a buffer for storing evaluations of func1d.
# remove the requested axis, and add the new ones on the end.
# laid out so that each write is contiguous.
# for a tuple index inds, buff[inds] = func1d(inarr_view[inds])
buff = zeros(inarr_view.shape[:-1] + res.shape, res.dtype)
# permutation of axes such that out = buff.transpose(buff_permute)
buff_dims = list(range(buff.ndim))
buff_permute = (
buff_dims[0:axis]
+ buff_dims[buff.ndim - res.ndim : buff.ndim]
+ buff_dims[axis : buff.ndim - res.ndim]
)
# matrices have a nasty __array_prepare__ and __array_wrap__
if not isinstance(res, matrix):
buff = res.__array_prepare__(buff)
# save the first result, then compute and save all remaining results
buff[ind0] = res
for ind in inds:
buff[ind] = asanyarray(func1d(inarr_view[ind], *args, **kwargs))
if not isinstance(res, matrix):
# wrap the array, to preserve subclasses
buff = res.__array_wrap__(buff)
# finally, rotate the inserted axes back to where they belong
return transpose(buff, buff_permute)
else:
# matrices have to be transposed first, because they collapse dimensions!
out_arr = transpose(buff, buff_permute)
return res.__array_wrap__(out_arr)
def apply_along_axis(func1d, axis, arr, *args, **kwargs):
"""
Apply a function to 1-D slices along the given axis.
Execute `func1d(a, *args)` where `func1d` operates on 1-D arrays and `a`
is a 1-D slice of `arr` along `axis`.
Parameters
----------
func1d : function
This function should accept 1-D arrays. It is applied to 1-D
slices of `arr` along the specified axis.
axis : integer
Axis along which `arr` is sliced.
arr : ndarray
Input array.
args : any
Additional arguments to `func1d`.
kwargs : any
Additional named arguments to `func1d`.
.. versionadded:: 1.9.0
Returns
-------
apply_along_axis : ndarray
The output array. The shape of `outarr` is identical to the shape of
`arr`, except along the `axis` dimension. This axis is removed, and
replaced with new dimensions equal to the shape of the return value
of `func1d`. So if `func1d` returns a scalar `outarr` will have one
fewer dimensions than `arr`.
See Also
--------
apply_over_axes : Apply a function repeatedly over multiple axes.
Examples
--------
>>> def my_func(a):
... \"\"\"Average first and last element of a 1-D array\"\"\"
... return (a[0] + a[-1]) * 0.5
>>> b = np.array([[1,2,3], [4,5,6], [7,8,9]])
>>> np.apply_along_axis(my_func, 0, b)
array([ 4., 5., 6.])
>>> np.apply_along_axis(my_func, 1, b)
array([ 2., 5., 8.])
For a function that returns a 1D array, the number of dimensions in
`outarr` is the same as `arr`.
>>> b = np.array([[8,1,7], [4,3,9], [5,2,6]])
>>> np.apply_along_axis(sorted, 1, b)
array([[1, 7, 8],
[3, 4, 9],
[2, 5, 6]])
For a function that returns a higher dimensional array, those dimensions
are inserted in place of the `axis` dimension.
>>> b = np.array([[1,2,3], [4,5,6], [7,8,9]])
>>> np.apply_along_axis(np.diag, -1, b)
array([[[1, 0, 0],
[0, 2, 0],
[0, 0, 3]],
[[4, 0, 0],
[0, 5, 0],
[0, 0, 6]],
[[7, 0, 0],
[0, 8, 0],
[0, 0, 9]]])
"""
# handle negative axes
arr = asanyarray(arr)
nd = arr.ndim
if not (-nd <= axis < nd):
raise IndexError('axis {0} out of bounds [-{1}, {1})'.format(axis, nd))
if axis < 0:
axis += nd
# arr, with the iteration axis at the end
in_dims = list(range(nd))
inarr_view = transpose(arr, in_dims[:axis] + in_dims[axis+1:] + [axis])
# compute indices for the iteration axes
inds = ndindex(inarr_view.shape[:-1])
# invoke the function on the first item
ind0 = next(inds)
res = asanyarray(func1d(inarr_view[ind0], *args, **kwargs))
# build a buffer for storing evaluations of func1d.
# remove the requested axis, and add the new ones on the end.
# laid out so that each write is contiguous.
# for a tuple index inds, buff[inds] = func1d(inarr_view[inds])
buff = zeros(inarr_view.shape[:-1] + res.shape, res.dtype)
# permutation of axes such that out = buff.transpose(buff_permute)
buff_dims = list(range(buff.ndim))
buff_permute = (
buff_dims[0 : axis] +
buff_dims[buff.ndim-res.ndim : buff.ndim] +
buff_dims[axis : buff.ndim-res.ndim]
)
# matrices have a nasty __array_prepare__ and __array_wrap__
if not isinstance(res, matrix):
buff = res.__array_prepare__(buff)
# save the first result, then compute and save all remaining results
buff[ind0] = res
for ind in inds:
buff[ind] = asanyarray(func1d(inarr_view[ind], *args, **kwargs))
if not isinstance(res, matrix):
# wrap the array, to preserve subclasses
buff = res.__array_wrap__(buff)
# finally, rotate the inserted axes back to where they belong
return transpose(buff, buff_permute)
else:
# matrices have to be transposed first, because they collapse dimensions!
out_arr = transpose(buff, buff_permute)
return res.__array_wrap__(out_arr)