Python Examples of numpy.core.multiarray.zeros

Source File: functions.py From Computable with MIT License

5 votes

def zeros(shape, typecode='l', savespace=0, dtype=None):
    """zeros(shape, dtype=int) returns an array of the given
    dimensions which is initialized to all zeros
    """
    dtype = convtypecode(typecode, dtype)
    return mu.zeros(shape, dtype)

Source File: functions.py From biskit with GNU General Public License v3.0

5 votes

def zeros(shape, typecode='l', savespace=0, dtype=None):
    """zeros(shape, dtype=int) returns an array of the given
    dimensions which is initialized to all zeros
    """
    dtype = convtypecode(typecode, dtype)
    return mu.zeros(shape, dtype)

Source File: high_speed_jacobian.py From GridCal with GNU General Public License v3.0

5 votes

def dSbus_dV(Ybus, V, I):
    """
    Calls functions to calculate dS/dV depending on whether Ybus is sparse or not
    """

    # I is substracted from Y*V,
    # therefore it must be negative for numba version of dSbus_dV if it is not zeros anyways
    # calculates sparse data
    dS_dVm, dS_dVa = dSbus_dV_numba_sparse(Ybus.data, Ybus.indptr, Ybus.indices, V, V / abs(V), I)
    # generate sparse CSR matrices with computed data and return them
    return sparse((dS_dVm, Ybus.indices, Ybus.indptr)), sparse((dS_dVa, Ybus.indices, Ybus.indptr))


# @jit(i8(c16[:], c16[:], i4[:], i4[:], i8[:], i8[:], f8[:], i8[:], i8[:]), nopython=True, cache=False)

Source File: high_speed_jacobian.py From GridCal with GNU General Public License v3.0

5 votes

def _create_J_with_numba(Ybus, V, pvpq, pq, pvpq_lookup, npv, npq):
    """

    :param Ybus:
    :param V:
    :param pvpq:
    :param pq:
    :param createJ:
    :param pvpq_lookup:
    :param npv:
    :param npq:
    :return:
    """
    Ibus = zeros(len(V), dtype=complex128)
    # create Jacobian from fast calc of dS_dV
    dVm_x, dVa_x = dSbus_dV_numba_sparse(Ybus.data, Ybus.indptr, Ybus.indices, V, V / abs(V), Ibus)

    # data in J, space preallocated is bigger than acutal Jx -> will be reduced later on
    Jx = empty(len(dVm_x) * 4, dtype=float64)
    # row pointer, dimension = pvpq.shape[0] + pq.shape[0] + 1
    Jp = zeros(pvpq.shape[0] + pq.shape[0] + 1, dtype=int32)
    # indices, same with the preallocated space (see Jx)
    Jj = empty(len(dVm_x) * 4, dtype=int32)

    # fill Jx, Jj and Jp
    # createJ(dVm_x, dVa_x, Ybus.indptr, Ybus.indices, pvpq_lookup, pvpq, pq, Jx, Jj, Jp)
    if len(pvpq) == len(pq):
        create_J2(dVm_x, dVa_x, Ybus.indptr, Ybus.indices, pvpq_lookup, pvpq, pq, Jx, Jj, Jp)
    else:
        create_J(dVm_x, dVa_x, Ybus.indptr, Ybus.indices, pvpq_lookup, pvpq, pq, Jx, Jj, Jp)

    # resize before generating the scipy sparse matrix
    Jx.resize(Jp[-1], refcheck=False)
    Jj.resize(Jp[-1], refcheck=False)

    # generate scipy sparse matrix
    dimJ = npv + npq + npq
    J = sparse((Jx, Jj, Jp), shape=(dimJ, dimJ))

    return J

Source File: numeric.py From auto-alt-text-lambda-api with MIT License

4 votes

def zeros_like(a, dtype=None, order='K', subok=True):
    """
    Return an array of zeros with the same shape and type as a given array.

    Parameters
    ----------
    a : array_like
        The shape and data-type of `a` define these same attributes of
        the returned array.
    dtype : data-type, optional
        Overrides the data type of the result.

        .. versionadded:: 1.6.0
    order : {'C', 'F', 'A', or 'K'}, optional
        Overrides the memory layout of the result. 'C' means C-order,
        'F' means F-order, 'A' means 'F' if `a` is Fortran contiguous,
        'C' otherwise. 'K' means match the layout of `a` as closely
        as possible.

        .. versionadded:: 1.6.0
    subok : bool, optional.
        If True, then the newly created array will use the sub-class
        type of 'a', otherwise it will be a base-class array. Defaults
        to True.

    Returns
    -------
    out : ndarray
        Array of zeros with the same shape and type as `a`.

    See Also
    --------
    ones_like : Return an array of ones with shape and type of input.
    empty_like : Return an empty array with shape and type of input.
    zeros : Return a new array setting values to zero.
    ones : Return a new array setting values to one.
    empty : Return a new uninitialized array.

    Examples
    --------
    >>> x = np.arange(6)
    >>> x = x.reshape((2, 3))
    >>> x
    array([[0, 1, 2],
           [3, 4, 5]])
    >>> np.zeros_like(x)
    array([[0, 0, 0],
           [0, 0, 0]])

    >>> y = np.arange(3, dtype=np.float)
    >>> y
    array([ 0.,  1.,  2.])
    >>> np.zeros_like(y)
    array([ 0.,  0.,  0.])

    """
    res = empty_like(a, dtype=dtype, order=order, subok=subok)
    # needed instead of a 0 to get same result as zeros for for string dtypes
    z = zeros(1, dtype=res.dtype)
    multiarray.copyto(res, z, casting='unsafe')
    return res

Source File: numeric.py From auto-alt-text-lambda-api with MIT License

4 votes

def ones(shape, dtype=None, order='C'):
    """
    Return a new array of given shape and type, filled with ones.

    Parameters
    ----------
    shape : int or sequence of ints
        Shape of the new array, e.g., ``(2, 3)`` or ``2``.
    dtype : data-type, optional
        The desired data-type for the array, e.g., `numpy.int8`.  Default is
        `numpy.float64`.
    order : {'C', 'F'}, optional
        Whether to store multidimensional data in C- or Fortran-contiguous
        (row- or column-wise) order in memory.

    Returns
    -------
    out : ndarray
        Array of ones with the given shape, dtype, and order.

    See Also
    --------
    zeros, ones_like

    Examples
    --------
    >>> np.ones(5)
    array([ 1.,  1.,  1.,  1.,  1.])

    >>> np.ones((5,), dtype=np.int)
    array([1, 1, 1, 1, 1])

    >>> np.ones((2, 1))
    array([[ 1.],
           [ 1.]])

    >>> s = (2,2)
    >>> np.ones(s)
    array([[ 1.,  1.],
           [ 1.,  1.]])

    """
    a = empty(shape, dtype, order)
    multiarray.copyto(a, 1, casting='unsafe')
    return a

Source File: numeric.py From auto-alt-text-lambda-api with MIT License

4 votes

def ones_like(a, dtype=None, order='K', subok=True):
    """
    Return an array of ones with the same shape and type as a given array.

    Parameters
    ----------
    a : array_like
        The shape and data-type of `a` define these same attributes of
        the returned array.
    dtype : data-type, optional
        Overrides the data type of the result.

        .. versionadded:: 1.6.0
    order : {'C', 'F', 'A', or 'K'}, optional
        Overrides the memory layout of the result. 'C' means C-order,
        'F' means F-order, 'A' means 'F' if `a` is Fortran contiguous,
        'C' otherwise. 'K' means match the layout of `a` as closely
        as possible.

        .. versionadded:: 1.6.0
    subok : bool, optional.
        If True, then the newly created array will use the sub-class
        type of 'a', otherwise it will be a base-class array. Defaults
        to True.

    Returns
    -------
    out : ndarray
        Array of ones with the same shape and type as `a`.

    See Also
    --------
    zeros_like : Return an array of zeros with shape and type of input.
    empty_like : Return an empty array with shape and type of input.
    zeros : Return a new array setting values to zero.
    ones : Return a new array setting values to one.
    empty : Return a new uninitialized array.

    Examples
    --------
    >>> x = np.arange(6)
    >>> x = x.reshape((2, 3))
    >>> x
    array([[0, 1, 2],
           [3, 4, 5]])
    >>> np.ones_like(x)
    array([[1, 1, 1],
           [1, 1, 1]])

    >>> y = np.arange(3, dtype=np.float)
    >>> y
    array([ 0.,  1.,  2.])
    >>> np.ones_like(y)
    array([ 1.,  1.,  1.])

    """
    res = empty_like(a, dtype=dtype, order=order, subok=subok)
    multiarray.copyto(res, 1, casting='unsafe')
    return res

Source File: numeric.py From auto-alt-text-lambda-api with MIT License

4 votes

def full(shape, fill_value, dtype=None, order='C'):
    """
    Return a new array of given shape and type, filled with `fill_value`.

    Parameters
    ----------
    shape : int or sequence of ints
        Shape of the new array, e.g., ``(2, 3)`` or ``2``.
    fill_value : scalar
        Fill value.
    dtype : data-type, optional
        The desired data-type for the array, e.g., `np.int8`.  Default
        is `float`, but will change to `np.array(fill_value).dtype` in a
        future release.
    order : {'C', 'F'}, optional
        Whether to store multidimensional data in C- or Fortran-contiguous
        (row- or column-wise) order in memory.

    Returns
    -------
    out : ndarray
        Array of `fill_value` with the given shape, dtype, and order.

    See Also
    --------
    zeros_like : Return an array of zeros with shape and type of input.
    ones_like : Return an array of ones with shape and type of input.
    empty_like : Return an empty array with shape and type of input.
    full_like : Fill an array with shape and type of input.
    zeros : Return a new array setting values to zero.
    ones : Return a new array setting values to one.
    empty : Return a new uninitialized array.

    Examples
    --------
    >>> np.full((2, 2), np.inf)
    array([[ inf,  inf],
           [ inf,  inf]])
    >>> np.full((2, 2), 10, dtype=np.int)
    array([[10, 10],
           [10, 10]])

    """
    a = empty(shape, dtype, order)
    if dtype is None and array(fill_value).dtype != a.dtype:
        warnings.warn(
            "in the future, full({0}, {1!r}) will return an array of {2!r}".
            format(shape, fill_value, array(fill_value).dtype), FutureWarning)
    multiarray.copyto(a, fill_value, casting='unsafe')
    return a

Source File: numeric.py From auto-alt-text-lambda-api with MIT License

4 votes

def full_like(a, fill_value, dtype=None, order='K', subok=True):
    """
    Return a full array with the same shape and type as a given array.

    Parameters
    ----------
    a : array_like
        The shape and data-type of `a` define these same attributes of
        the returned array.
    fill_value : scalar
        Fill value.
    dtype : data-type, optional
        Overrides the data type of the result.
    order : {'C', 'F', 'A', or 'K'}, optional
        Overrides the memory layout of the result. 'C' means C-order,
        'F' means F-order, 'A' means 'F' if `a` is Fortran contiguous,
        'C' otherwise. 'K' means match the layout of `a` as closely
        as possible.
    subok : bool, optional.
        If True, then the newly created array will use the sub-class
        type of 'a', otherwise it will be a base-class array. Defaults
        to True.

    Returns
    -------
    out : ndarray
        Array of `fill_value` with the same shape and type as `a`.

    See Also
    --------
    zeros_like : Return an array of zeros with shape and type of input.
    ones_like : Return an array of ones with shape and type of input.
    empty_like : Return an empty array with shape and type of input.
    zeros : Return a new array setting values to zero.
    ones : Return a new array setting values to one.
    empty : Return a new uninitialized array.
    full : Fill a new array.

    Examples
    --------
    >>> x = np.arange(6, dtype=np.int)
    >>> np.full_like(x, 1)
    array([1, 1, 1, 1, 1, 1])
    >>> np.full_like(x, 0.1)
    array([0, 0, 0, 0, 0, 0])
    >>> np.full_like(x, 0.1, dtype=np.double)
    array([ 0.1,  0.1,  0.1,  0.1,  0.1,  0.1])
    >>> np.full_like(x, np.nan, dtype=np.double)
    array([ nan,  nan,  nan,  nan,  nan,  nan])

    >>> y = np.arange(6, dtype=np.double)
    >>> np.full_like(y, 0.1)
    array([ 0.1,  0.1,  0.1,  0.1,  0.1,  0.1])

    """
    res = empty_like(a, dtype=dtype, order=order, subok=subok)
    multiarray.copyto(res, fill_value, casting='unsafe')
    return res

Source File: high_speed_jacobian.py From GridCal with GNU General Public License v3.0

4 votes

def dSbus_dV_numba_sparse(Yx, Yp, Yj, V, Vnorm, Ibus): # pragma: no cover
    """Computes partial derivatives of power injection w.r.t. voltage.

    Calculates faster with numba and sparse matrices.

    Input: Ybus in CSR sparse form (Yx = data, Yp = indptr, Yj = indices), V and Vnorm (= V / abs(V))

    OUTPUT: data from CSR form of dS_dVm, dS_dVa
    (index pointer and indices are the same as the ones from Ybus)

    Translation of: dS_dVm = dS_dVm = diagV * conj(Ybus * diagVnorm) + conj(diagIbus) * diagVnorm
                             dS_dVa = 1j * diagV * conj(diagIbus - Ybus * diagV)
    """

    # transform input

    # init buffer vector
    buffer = zeros(len(V), dtype=complex128)
    dS_dVm = Yx.copy()
    dS_dVa = Yx.copy()

    # iterate through sparse matrix
    for r in range(len(Yp) - 1):
        for k in range(Yp[r], Yp[r + 1]):
            # Ibus = Ybus * V
            buffer[r] += Yx[k] * V[Yj[k]]
            # Ybus * diag(Vnorm)
            dS_dVm[k] *= Vnorm[Yj[k]]
            # Ybus * diag(V)
            dS_dVa[k] *= V[Yj[k]]

        Ibus[r] += buffer[r]

        # conj(diagIbus) * diagVnorm
        buffer[r] = conj(buffer[r]) * Vnorm[r]

    for r in range(len(Yp) - 1):
        for k in range(Yp[r], Yp[r + 1]):
            # diag(V) * conj(Ybus * diagVnorm)
            dS_dVm[k] = conj(dS_dVm[k]) * V[r]

            if r == Yj[k]:
                # diagonal elements
                dS_dVa[k] = -Ibus[r] + dS_dVa[k]
                dS_dVm[k] += buffer[r]

            # 1j * diagV * conj(diagIbus - Ybus * diagV)
            dS_dVa[k] = conj(-dS_dVa[k]) * (1j * V[r])

    return dS_dVm, dS_dVa