diff options
Diffstat (limited to 'numpy/lib/function_base.py')
| -rw-r--r-- | numpy/lib/function_base.py | 185 |
1 files changed, 136 insertions, 49 deletions
diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py index cf6f4891c..d33a0fa7d 100644 --- a/numpy/lib/function_base.py +++ b/numpy/lib/function_base.py @@ -431,10 +431,13 @@ def asarray_chkfinite(a, dtype=None, order=None): of lists and ndarrays. Success requires no NaNs or Infs. dtype : data-type, optional By default, the data-type is inferred from the input data. - order : {'C', 'F'}, optional - Whether to use row-major (C-style) or - column-major (Fortran-style) memory representation. - Defaults to 'C'. + order : {'C', 'F', 'A', 'K'}, optional + Memory layout. 'A' and 'K' depend on the order of input array a. + 'C' row-major (C-style), + 'F' column-major (Fortran-style) memory representation. + 'A' (any) means 'F' if `a` is Fortran contiguous, 'C' otherwise + 'K' (keep) preserve input order + Defaults to 'C'. Returns ------- @@ -843,7 +846,7 @@ def gradient(f, *varargs, axis=None, edge_order=1): Returns ------- gradient : ndarray or list of ndarray - A set of ndarrays (or a single ndarray if there is only one dimension) + A list of ndarrays (or a single ndarray if there is only one dimension) corresponding to the derivatives of f with respect to each dimension. Each derivative has the same shape as f. @@ -1287,7 +1290,7 @@ def _interp_dispatcher(x, xp, fp, left=None, right=None, period=None): @array_function_dispatch(_interp_dispatcher) def interp(x, xp, fp, left=None, right=None, period=None): """ - One-dimensional linear interpolation. + One-dimensional linear interpolation for monotonically increasing sample points. Returns the one-dimensional piecewise linear interpolant to a function with given discrete data points (`xp`, `fp`), evaluated at `x`. @@ -1334,8 +1337,8 @@ def interp(x, xp, fp, left=None, right=None, period=None): -------- scipy.interpolate - Notes - ----- + Warnings + -------- The x-coordinate sequence is expected to be increasing, but this is not explicitly enforced. However, if the sequence `xp` is non-increasing, interpolation results are meaningless. @@ -1447,7 +1450,7 @@ def angle(z, deg=False): The counterclockwise angle from the positive real axis on the complex plane in the range ``(-pi, pi]``, with dtype as numpy.float64. - ..versionchanged:: 1.16.0 + .. versionchanged:: 1.16.0 This function works on subclasses of ndarray like `ma.array`. See Also @@ -1622,6 +1625,7 @@ def trim_zeros(filt, trim='fb'): [1, 2] """ + first = 0 trim = trim.upper() if 'F' in trim: @@ -1931,8 +1935,8 @@ class vectorize: .. versionadded:: 1.7.0 cache : bool, optional - If `True`, then cache the first function call that determines the number - of outputs if `otypes` is not provided. + If `True`, then cache the first function call that determines the number + of outputs if `otypes` is not provided. .. versionadded:: 1.7.0 @@ -2264,13 +2268,13 @@ class vectorize: def _cov_dispatcher(m, y=None, rowvar=None, bias=None, ddof=None, - fweights=None, aweights=None): + fweights=None, aweights=None, *, dtype=None): return (m, y, fweights, aweights) @array_function_dispatch(_cov_dispatcher) def cov(m, y=None, rowvar=True, bias=False, ddof=None, fweights=None, - aweights=None): + aweights=None, *, dtype=None): """ Estimate a covariance matrix, given data and weights. @@ -2321,6 +2325,11 @@ def cov(m, y=None, rowvar=True, bias=False, ddof=None, fweights=None, weights can be used to assign probabilities to observation vectors. .. versionadded:: 1.10 + dtype : data-type, optional + Data-type of the result. By default, the return data-type will have + at least `numpy.float64` precision. + + .. versionadded:: 1.20 Returns ------- @@ -2396,13 +2405,16 @@ def cov(m, y=None, rowvar=True, bias=False, ddof=None, fweights=None, if m.ndim > 2: raise ValueError("m has more than 2 dimensions") - if y is None: - dtype = np.result_type(m, np.float64) - else: + if y is not None: y = np.asarray(y) if y.ndim > 2: raise ValueError("y has more than 2 dimensions") - dtype = np.result_type(m, y, np.float64) + + if dtype is None: + if y is None: + dtype = np.result_type(m, np.float64) + else: + dtype = np.result_type(m, y, np.float64) X = array(m, ndmin=2, dtype=dtype) if not rowvar and X.shape[0] != 1: @@ -2482,12 +2494,14 @@ def cov(m, y=None, rowvar=True, bias=False, ddof=None, fweights=None, return c.squeeze() -def _corrcoef_dispatcher(x, y=None, rowvar=None, bias=None, ddof=None): +def _corrcoef_dispatcher(x, y=None, rowvar=None, bias=None, ddof=None, *, + dtype=None): return (x, y) @array_function_dispatch(_corrcoef_dispatcher) -def corrcoef(x, y=None, rowvar=True, bias=np._NoValue, ddof=np._NoValue): +def corrcoef(x, y=None, rowvar=True, bias=np._NoValue, ddof=np._NoValue, *, + dtype=None): """ Return Pearson product-moment correlation coefficients. @@ -2521,6 +2535,11 @@ def corrcoef(x, y=None, rowvar=True, bias=np._NoValue, ddof=np._NoValue): Has no effect, do not use. .. deprecated:: 1.10.0 + dtype : data-type, optional + Data-type of the result. By default, the return data-type will have + at least `numpy.float64` precision. + + .. versionadded:: 1.20 Returns ------- @@ -2544,12 +2563,75 @@ def corrcoef(x, y=None, rowvar=True, bias=np._NoValue, ddof=np._NoValue): arguments had no effect on the return values of the function and can be safely ignored in this and previous versions of numpy. + Examples + -------- + In this example we generate two random arrays, ``xarr`` and ``yarr``, and + compute the row-wise and column-wise Pearson correlation coefficients, + ``R``. Since ``rowvar`` is true by default, we first find the row-wise + Pearson correlation coefficients between the variables of ``xarr``. + + >>> import numpy as np + >>> rng = np.random.default_rng(seed=42) + >>> xarr = rng.random((3, 3)) + >>> xarr + array([[0.77395605, 0.43887844, 0.85859792], + [0.69736803, 0.09417735, 0.97562235], + [0.7611397 , 0.78606431, 0.12811363]]) + >>> R1 = np.corrcoef(xarr) + >>> R1 + array([[ 1. , 0.99256089, -0.68080986], + [ 0.99256089, 1. , -0.76492172], + [-0.68080986, -0.76492172, 1. ]]) + + If we add another set of variables and observations ``yarr``, we can + compute the row-wise Pearson correlation coefficients between the + variables in ``xarr`` and ``yarr``. + + >>> yarr = rng.random((3, 3)) + >>> yarr + array([[0.45038594, 0.37079802, 0.92676499], + [0.64386512, 0.82276161, 0.4434142 ], + [0.22723872, 0.55458479, 0.06381726]]) + >>> R2 = np.corrcoef(xarr, yarr) + >>> R2 + array([[ 1. , 0.99256089, -0.68080986, 0.75008178, -0.934284 , + -0.99004057], + [ 0.99256089, 1. , -0.76492172, 0.82502011, -0.97074098, + -0.99981569], + [-0.68080986, -0.76492172, 1. , -0.99507202, 0.89721355, + 0.77714685], + [ 0.75008178, 0.82502011, -0.99507202, 1. , -0.93657855, + -0.83571711], + [-0.934284 , -0.97074098, 0.89721355, -0.93657855, 1. , + 0.97517215], + [-0.99004057, -0.99981569, 0.77714685, -0.83571711, 0.97517215, + 1. ]]) + + Finally if we use the option ``rowvar=False``, the columns are now + being treated as the variables and we will find the column-wise Pearson + correlation coefficients between variables in ``xarr`` and ``yarr``. + + >>> R3 = np.corrcoef(xarr, yarr, rowvar=False) + >>> R3 + array([[ 1. , 0.77598074, -0.47458546, -0.75078643, -0.9665554 , + 0.22423734], + [ 0.77598074, 1. , -0.92346708, -0.99923895, -0.58826587, + -0.44069024], + [-0.47458546, -0.92346708, 1. , 0.93773029, 0.23297648, + 0.75137473], + [-0.75078643, -0.99923895, 0.93773029, 1. , 0.55627469, + 0.47536961], + [-0.9665554 , -0.58826587, 0.23297648, 0.55627469, 1. , + -0.46666491], + [ 0.22423734, -0.44069024, 0.75137473, 0.47536961, -0.46666491, + 1. ]]) + """ if bias is not np._NoValue or ddof is not np._NoValue: # 2015-03-15, 1.10 warnings.warn('bias and ddof have no effect and are deprecated', DeprecationWarning, stacklevel=3) - c = cov(x, y, rowvar) + c = cov(x, y, rowvar, dtype=dtype) try: d = diag(c) except ValueError: @@ -2666,8 +2748,8 @@ def blackman(M): return array([]) if M == 1: return ones(1, float) - n = arange(0, M) - return 0.42 - 0.5*cos(2.0*pi*n/(M-1)) + 0.08*cos(4.0*pi*n/(M-1)) + n = arange(1-M, M, 2) + return 0.42 + 0.5*cos(pi*n/(M-1)) + 0.08*cos(2.0*pi*n/(M-1)) @set_module('numpy') @@ -2775,8 +2857,8 @@ def bartlett(M): return array([]) if M == 1: return ones(1, float) - n = arange(0, M) - return where(less_equal(n, (M-1)/2.0), 2.0*n/(M-1), 2.0 - 2.0*n/(M-1)) + n = arange(1-M, M, 2) + return where(less_equal(n, 0), 1 + n/(M-1), 1 - n/(M-1)) @set_module('numpy') @@ -2879,8 +2961,8 @@ def hanning(M): return array([]) if M == 1: return ones(1, float) - n = arange(0, M) - return 0.5 - 0.5*cos(2.0*pi*n/(M-1)) + n = arange(1-M, M, 2) + return 0.5 + 0.5*cos(pi*n/(M-1)) @set_module('numpy') @@ -2979,8 +3061,8 @@ def hamming(M): return array([]) if M == 1: return ones(1, float) - n = arange(0, M) - return 0.54 - 0.46*cos(2.0*pi*n/(M-1)) + n = arange(1-M, M, 2) + return 0.54 + 0.46*cos(pi*n/(M-1)) ## Code from cephes for i0 @@ -3076,25 +3158,18 @@ def i0(x): """ Modified Bessel function of the first kind, order 0. - Usually denoted :math:`I_0`. This function does broadcast, but will *not* - "up-cast" int dtype arguments unless accompanied by at least one float or - complex dtype argument (see Raises below). + Usually denoted :math:`I_0`. Parameters ---------- - x : array_like, dtype float or complex + x : array_like of float Argument of the Bessel function. Returns ------- - out : ndarray, shape = x.shape, dtype = x.dtype + out : ndarray, shape = x.shape, dtype = float The modified Bessel function evaluated at each of the elements of `x`. - Raises - ------ - TypeError: array cannot be safely cast to required type - If argument consists exclusively of int dtypes. - See Also -------- scipy.special.i0, scipy.special.iv, scipy.special.ive @@ -3124,12 +3199,16 @@ def i0(x): Examples -------- >>> np.i0(0.) - array(1.0) # may vary - >>> np.i0([0., 1. + 2j]) - array([ 1.00000000+0.j , 0.18785373+0.64616944j]) # may vary + array(1.0) + >>> np.i0([0, 1, 2, 3]) + array([1. , 1.26606588, 2.2795853 , 4.88079259]) """ x = np.asanyarray(x) + if x.dtype.kind == 'c': + raise TypeError("i0 not supported for complex values") + if x.dtype.kind != 'f': + x = x.astype(float) x = np.abs(x) return piecewise(x, [x <= 8.0], [_i0_1, _i0_2]) @@ -3879,7 +3958,13 @@ def _quantile_is_valid(q): def _lerp(a, b, t, out=None): """ Linearly interpolate from a to b by a factor of t """ - return add(a*(1 - t), b*t, out=out) + diff_b_a = subtract(b, a) + # asanyarray is a stop-gap until gh-13105 + lerp_interpolation = asanyarray(add(a, diff_b_a*t, out=out)) + subtract(b, diff_b_a * (1 - t), out=lerp_interpolation, where=t>=0.5) + if lerp_interpolation.ndim == 0 and out is None: + lerp_interpolation = lerp_interpolation[()] # unpack 0d arrays + return lerp_interpolation def _quantile_ureduce_func(a, q, axis=None, out=None, overwrite_input=False, @@ -4015,9 +4100,12 @@ def trapz(y, x=None, dx=1.0, axis=-1): Returns ------- - trapz : float - Definite integral as approximated by trapezoidal rule. - + trapz : float or ndarray + Definite integral of 'y' = n-dimensional array as approximated along + a single axis by the trapezoidal rule. If 'y' is a 1-dimensional array, + then the result is a float. If 'n' is greater than 1, then the result + is an 'n-1' dimensional array. + See Also -------- sum, cumsum @@ -4159,10 +4247,9 @@ def meshgrid(*xi, copy=True, sparse=False, indexing='xy'): See Also -------- - index_tricks.mgrid : Construct a multi-dimensional "meshgrid" - using indexing notation. - index_tricks.ogrid : Construct an open multi-dimensional "meshgrid" - using indexing notation. + mgrid : Construct a multi-dimensional "meshgrid" using indexing notation. + ogrid : Construct an open multi-dimensional "meshgrid" using indexing + notation. Examples -------- |