Mercurial > hg > vamp-build-and-test
diff DEPENDENCIES/mingw32/Python27/Lib/site-packages/numpy/lib/arraysetops.py @ 87:2a2c65a20a8b
Add Python libs and headers
author | Chris Cannam |
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date | Wed, 25 Feb 2015 14:05:22 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DEPENDENCIES/mingw32/Python27/Lib/site-packages/numpy/lib/arraysetops.py Wed Feb 25 14:05:22 2015 +0000 @@ -0,0 +1,463 @@ +""" +Set operations for 1D numeric arrays based on sorting. + +:Contains: + ediff1d, + unique, + intersect1d, + setxor1d, + in1d, + union1d, + setdiff1d + +:Notes: + +For floating point arrays, inaccurate results may appear due to usual round-off +and floating point comparison issues. + +Speed could be gained in some operations by an implementation of +sort(), that can provide directly the permutation vectors, avoiding +thus calls to argsort(). + +To do: Optionally return indices analogously to unique for all functions. + +:Author: Robert Cimrman + +""" +from __future__ import division, absolute_import, print_function + +import numpy as np + + +__all__ = [ + 'ediff1d', 'intersect1d', 'setxor1d', 'union1d', 'setdiff1d', 'unique', + 'in1d' + ] + + +def ediff1d(ary, to_end=None, to_begin=None): + """ + The differences between consecutive elements of an array. + + Parameters + ---------- + ary : array_like + If necessary, will be flattened before the differences are taken. + to_end : array_like, optional + Number(s) to append at the end of the returned differences. + to_begin : array_like, optional + Number(s) to prepend at the beginning of the returned differences. + + Returns + ------- + ediff1d : ndarray + The differences. Loosely, this is ``ary.flat[1:] - ary.flat[:-1]``. + + See Also + -------- + diff, gradient + + Notes + ----- + When applied to masked arrays, this function drops the mask information + if the `to_begin` and/or `to_end` parameters are used. + + Examples + -------- + >>> x = np.array([1, 2, 4, 7, 0]) + >>> np.ediff1d(x) + array([ 1, 2, 3, -7]) + + >>> np.ediff1d(x, to_begin=-99, to_end=np.array([88, 99])) + array([-99, 1, 2, 3, -7, 88, 99]) + + The returned array is always 1D. + + >>> y = [[1, 2, 4], [1, 6, 24]] + >>> np.ediff1d(y) + array([ 1, 2, -3, 5, 18]) + + """ + ary = np.asanyarray(ary).flat + ed = ary[1:] - ary[:-1] + arrays = [ed] + if to_begin is not None: + arrays.insert(0, to_begin) + if to_end is not None: + arrays.append(to_end) + + if len(arrays) != 1: + # We'll save ourselves a copy of a potentially large array in + # the common case where neither to_begin or to_end was given. + ed = np.hstack(arrays) + + return ed + +def unique(ar, return_index=False, return_inverse=False, return_counts=False): + """ + Find the unique elements of an array. + + Returns the sorted unique elements of an array. There are two optional + outputs in addition to the unique elements: the indices of the input array + that give the unique values, and the indices of the unique array that + reconstruct the input array. + + Parameters + ---------- + ar : array_like + Input array. This will be flattened if it is not already 1-D. + return_index : bool, optional + If True, also return the indices of `ar` that result in the unique + array. + return_inverse : bool, optional + If True, also return the indices of the unique array that can be used + to reconstruct `ar`. + return_counts : bool, optional + .. versionadded:: 1.9.0 + If True, also return the number of times each unique value comes up + in `ar`. + + Returns + ------- + unique : ndarray + The sorted unique values. + unique_indices : ndarray, optional + The indices of the first occurrences of the unique values in the + (flattened) original array. Only provided if `return_index` is True. + unique_inverse : ndarray, optional + The indices to reconstruct the (flattened) original array from the + unique array. Only provided if `return_inverse` is True. + unique_counts : ndarray, optional + .. versionadded:: 1.9.0 + The number of times each of the unique values comes up in the + original array. Only provided if `return_counts` is True. + + See Also + -------- + numpy.lib.arraysetops : Module with a number of other functions for + performing set operations on arrays. + + Examples + -------- + >>> np.unique([1, 1, 2, 2, 3, 3]) + array([1, 2, 3]) + >>> a = np.array([[1, 1], [2, 3]]) + >>> np.unique(a) + array([1, 2, 3]) + + Return the indices of the original array that give the unique values: + + >>> a = np.array(['a', 'b', 'b', 'c', 'a']) + >>> u, indices = np.unique(a, return_index=True) + >>> u + array(['a', 'b', 'c'], + dtype='|S1') + >>> indices + array([0, 1, 3]) + >>> a[indices] + array(['a', 'b', 'c'], + dtype='|S1') + + Reconstruct the input array from the unique values: + + >>> a = np.array([1, 2, 6, 4, 2, 3, 2]) + >>> u, indices = np.unique(a, return_inverse=True) + >>> u + array([1, 2, 3, 4, 6]) + >>> indices + array([0, 1, 4, 3, 1, 2, 1]) + >>> u[indices] + array([1, 2, 6, 4, 2, 3, 2]) + + """ + ar = np.asanyarray(ar).flatten() + + optional_indices = return_index or return_inverse + optional_returns = optional_indices or return_counts + + if ar.size == 0: + if not optional_returns: + ret = ar + else: + ret = (ar,) + if return_index: + ret += (np.empty(0, np.bool),) + if return_inverse: + ret += (np.empty(0, np.bool),) + if return_counts: + ret += (np.empty(0, np.intp),) + return ret + + if optional_indices: + perm = ar.argsort(kind='mergesort' if return_index else 'quicksort') + aux = ar[perm] + else: + ar.sort() + aux = ar + flag = np.concatenate(([True], aux[1:] != aux[:-1])) + + if not optional_returns: + ret = aux[flag] + else: + ret = (aux[flag],) + if return_index: + ret += (perm[flag],) + if return_inverse: + iflag = np.cumsum(flag) - 1 + iperm = perm.argsort() + ret += (np.take(iflag, iperm),) + if return_counts: + idx = np.concatenate(np.nonzero(flag) + ([ar.size],)) + ret += (np.diff(idx),) + return ret + +def intersect1d(ar1, ar2, assume_unique=False): + """ + Find the intersection of two arrays. + + Return the sorted, unique values that are in both of the input arrays. + + Parameters + ---------- + ar1, ar2 : array_like + Input arrays. + assume_unique : bool + If True, the input arrays are both assumed to be unique, which + can speed up the calculation. Default is False. + + Returns + ------- + intersect1d : ndarray + Sorted 1D array of common and unique elements. + + See Also + -------- + numpy.lib.arraysetops : Module with a number of other functions for + performing set operations on arrays. + + Examples + -------- + >>> np.intersect1d([1, 3, 4, 3], [3, 1, 2, 1]) + array([1, 3]) + + """ + if not assume_unique: + # Might be faster than unique( intersect1d( ar1, ar2 ) )? + ar1 = unique(ar1) + ar2 = unique(ar2) + aux = np.concatenate((ar1, ar2)) + aux.sort() + return aux[:-1][aux[1:] == aux[:-1]] + +def setxor1d(ar1, ar2, assume_unique=False): + """ + Find the set exclusive-or of two arrays. + + Return the sorted, unique values that are in only one (not both) of the + input arrays. + + Parameters + ---------- + ar1, ar2 : array_like + Input arrays. + assume_unique : bool + If True, the input arrays are both assumed to be unique, which + can speed up the calculation. Default is False. + + Returns + ------- + setxor1d : ndarray + Sorted 1D array of unique values that are in only one of the input + arrays. + + Examples + -------- + >>> a = np.array([1, 2, 3, 2, 4]) + >>> b = np.array([2, 3, 5, 7, 5]) + >>> np.setxor1d(a,b) + array([1, 4, 5, 7]) + + """ + if not assume_unique: + ar1 = unique(ar1) + ar2 = unique(ar2) + + aux = np.concatenate((ar1, ar2)) + if aux.size == 0: + return aux + + aux.sort() +# flag = ediff1d( aux, to_end = 1, to_begin = 1 ) == 0 + flag = np.concatenate(([True], aux[1:] != aux[:-1], [True])) +# flag2 = ediff1d( flag ) == 0 + flag2 = flag[1:] == flag[:-1] + return aux[flag2] + +def in1d(ar1, ar2, assume_unique=False, invert=False): + """ + Test whether each element of a 1-D array is also present in a second array. + + Returns a boolean array the same length as `ar1` that is True + where an element of `ar1` is in `ar2` and False otherwise. + + Parameters + ---------- + ar1 : (M,) array_like + Input array. + ar2 : array_like + The values against which to test each value of `ar1`. + assume_unique : bool, optional + If True, the input arrays are both assumed to be unique, which + can speed up the calculation. Default is False. + invert : bool, optional + If True, the values in the returned array are inverted (that is, + False where an element of `ar1` is in `ar2` and True otherwise). + Default is False. ``np.in1d(a, b, invert=True)`` is equivalent + to (but is faster than) ``np.invert(in1d(a, b))``. + + .. versionadded:: 1.8.0 + + Returns + ------- + in1d : (M,) ndarray, bool + The values `ar1[in1d]` are in `ar2`. + + See Also + -------- + numpy.lib.arraysetops : Module with a number of other functions for + performing set operations on arrays. + + Notes + ----- + `in1d` can be considered as an element-wise function version of the + python keyword `in`, for 1-D sequences. ``in1d(a, b)`` is roughly + equivalent to ``np.array([item in b for item in a])``. + + .. versionadded:: 1.4.0 + + Examples + -------- + >>> test = np.array([0, 1, 2, 5, 0]) + >>> states = [0, 2] + >>> mask = np.in1d(test, states) + >>> mask + array([ True, False, True, False, True], dtype=bool) + >>> test[mask] + array([0, 2, 0]) + >>> mask = np.in1d(test, states, invert=True) + >>> mask + array([False, True, False, True, False], dtype=bool) + >>> test[mask] + array([1, 5]) + """ + # Ravel both arrays, behavior for the first array could be different + ar1 = np.asarray(ar1).ravel() + ar2 = np.asarray(ar2).ravel() + + # This code is significantly faster when the condition is satisfied. + if len(ar2) < 10 * len(ar1) ** 0.145: + if invert: + mask = np.ones(len(ar1), dtype=np.bool) + for a in ar2: + mask &= (ar1 != a) + else: + mask = np.zeros(len(ar1), dtype=np.bool) + for a in ar2: + mask |= (ar1 == a) + return mask + + # Otherwise use sorting + if not assume_unique: + ar1, rev_idx = np.unique(ar1, return_inverse=True) + ar2 = np.unique(ar2) + + ar = np.concatenate((ar1, ar2)) + # We need this to be a stable sort, so always use 'mergesort' + # here. The values from the first array should always come before + # the values from the second array. + order = ar.argsort(kind='mergesort') + sar = ar[order] + if invert: + bool_ar = (sar[1:] != sar[:-1]) + else: + bool_ar = (sar[1:] == sar[:-1]) + flag = np.concatenate((bool_ar, [invert])) + indx = order.argsort(kind='mergesort')[:len(ar1)] + + if assume_unique: + return flag[indx] + else: + return flag[indx][rev_idx] + +def union1d(ar1, ar2): + """ + Find the union of two arrays. + + Return the unique, sorted array of values that are in either of the two + input arrays. + + Parameters + ---------- + ar1, ar2 : array_like + Input arrays. They are flattened if they are not already 1D. + + Returns + ------- + union1d : ndarray + Unique, sorted union of the input arrays. + + See Also + -------- + numpy.lib.arraysetops : Module with a number of other functions for + performing set operations on arrays. + + Examples + -------- + >>> np.union1d([-1, 0, 1], [-2, 0, 2]) + array([-2, -1, 0, 1, 2]) + + """ + return unique(np.concatenate((ar1, ar2))) + +def setdiff1d(ar1, ar2, assume_unique=False): + """ + Find the set difference of two arrays. + + Return the sorted, unique values in `ar1` that are not in `ar2`. + + Parameters + ---------- + ar1 : array_like + Input array. + ar2 : array_like + Input comparison array. + assume_unique : bool + If True, the input arrays are both assumed to be unique, which + can speed up the calculation. Default is False. + + Returns + ------- + setdiff1d : ndarray + Sorted 1D array of values in `ar1` that are not in `ar2`. + + See Also + -------- + numpy.lib.arraysetops : Module with a number of other functions for + performing set operations on arrays. + + Examples + -------- + >>> a = np.array([1, 2, 3, 2, 4, 1]) + >>> b = np.array([3, 4, 5, 6]) + >>> np.setdiff1d(a, b) + array([1, 2]) + + """ + if not assume_unique: + ar1 = unique(ar1) + ar2 = unique(ar2) + aux = in1d(ar1, ar2, assume_unique=True) + if aux.size == 0: + return aux + else: + return np.asarray(ar1)[aux == 0]