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"""A cache for storing small matrices in multiple formats.""" |
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from sympy.core.numbers import (I, Rational, pi) |
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from sympy.core.power import Pow |
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from sympy.functions.elementary.exponential import exp |
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from sympy.matrices.dense import Matrix |
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from sympy.physics.quantum.matrixutils import ( |
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to_sympy, to_numpy, to_scipy_sparse |
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) |
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class MatrixCache: |
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"""A cache for small matrices in different formats. |
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This class takes small matrices in the standard ``sympy.Matrix`` format, |
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and then converts these to both ``numpy.matrix`` and |
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``scipy.sparse.csr_matrix`` matrices. These matrices are then stored for |
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future recovery. |
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""" |
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def __init__(self, dtype='complex'): |
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self._cache = {} |
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self.dtype = dtype |
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def cache_matrix(self, name, m): |
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"""Cache a matrix by its name. |
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Parameters |
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---------- |
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name : str |
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A descriptive name for the matrix, like "identity2". |
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m : list of lists |
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The raw matrix data as a SymPy Matrix. |
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""" |
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try: |
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self._sympy_matrix(name, m) |
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except ImportError: |
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pass |
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try: |
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self._numpy_matrix(name, m) |
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except ImportError: |
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pass |
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try: |
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self._scipy_sparse_matrix(name, m) |
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except ImportError: |
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pass |
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def get_matrix(self, name, format): |
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"""Get a cached matrix by name and format. |
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Parameters |
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---------- |
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name : str |
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A descriptive name for the matrix, like "identity2". |
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format : str |
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The format desired ('sympy', 'numpy', 'scipy.sparse') |
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""" |
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m = self._cache.get((name, format)) |
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if m is not None: |
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return m |
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raise NotImplementedError( |
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'Matrix with name %s and format %s is not available.' % |
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(name, format) |
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) |
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def _store_matrix(self, name, format, m): |
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self._cache[(name, format)] = m |
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def _sympy_matrix(self, name, m): |
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self._store_matrix(name, 'sympy', to_sympy(m)) |
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def _numpy_matrix(self, name, m): |
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m = to_numpy(m, dtype=self.dtype) |
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self._store_matrix(name, 'numpy', m) |
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def _scipy_sparse_matrix(self, name, m): |
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m = to_scipy_sparse(m, dtype=self.dtype) |
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self._store_matrix(name, 'scipy.sparse', m) |
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sqrt2_inv = Pow(2, Rational(-1, 2), evaluate=False) |
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matrix_cache = MatrixCache() |
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matrix_cache.cache_matrix('eye2', Matrix([[1, 0], [0, 1]])) |
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matrix_cache.cache_matrix('op11', Matrix([[0, 0], [0, 1]])) |
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matrix_cache.cache_matrix('op00', Matrix([[1, 0], [0, 0]])) |
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matrix_cache.cache_matrix('op10', Matrix([[0, 0], [1, 0]])) |
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matrix_cache.cache_matrix('op01', Matrix([[0, 1], [0, 0]])) |
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matrix_cache.cache_matrix('X', Matrix([[0, 1], [1, 0]])) |
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matrix_cache.cache_matrix('Y', Matrix([[0, -I], [I, 0]])) |
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matrix_cache.cache_matrix('Z', Matrix([[1, 0], [0, -1]])) |
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matrix_cache.cache_matrix('S', Matrix([[1, 0], [0, I]])) |
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matrix_cache.cache_matrix('T', Matrix([[1, 0], [0, exp(I*pi/4)]])) |
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matrix_cache.cache_matrix('H', sqrt2_inv*Matrix([[1, 1], [1, -1]])) |
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matrix_cache.cache_matrix('Hsqrt2', Matrix([[1, 1], [1, -1]])) |
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matrix_cache.cache_matrix( |
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'SWAP', Matrix([[1, 0, 0, 0], [0, 0, 1, 0], [0, 1, 0, 0], [0, 0, 0, 1]])) |
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matrix_cache.cache_matrix('ZX', sqrt2_inv*Matrix([[1, 1], [1, -1]])) |
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matrix_cache.cache_matrix('ZY', Matrix([[I, 0], [0, -I]])) |
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