Source code for cvxpy.atoms.affine.reshape

"""
Copyright 2013 Steven Diamond

This file is part of CVXPY.

CVXPY is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

CVXPY is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with CVXPY.  If not, see <http://www.gnu.org/licenses/>.
"""

from cvxpy.atoms.affine.affine_atom import AffAtom
import cvxpy.lin_ops.lin_utils as lu
import numpy as np


[docs]class reshape(AffAtom): """Reshapes the expression. Vectorizes the expression then unvectorizes it into the new shape. The entries are reshaped and stored in column-major order, also known as Fortran order. Parameters ---------- expr : Expression The expression to promote. shape : tuple The shape to promote to. """ def __init__(self, expr, shape): self._shape = shape super(reshape, self).__init__(expr) @AffAtom.numpy_numeric def numeric(self, values): """Reshape the value. """ return np.reshape(values[0], self.shape, "F") def validate_arguments(self): """Checks that the new shape has the same number of entries as the old. """ old_len = self.args[0].size new_len = np.prod(self._shape, dtype=int) if not old_len == new_len: raise ValueError( "Invalid reshape dimensions %s." % (self._shape,) ) def shape_from_args(self): """Returns the shape from the rows, cols arguments. """ return self._shape def get_data(self): """Returns info needed to reconstruct the expression besides the args. """ return [self._shape] @staticmethod def graph_implementation(arg_objs, shape, data=None): """Convolve two vectors. Parameters ---------- arg_objs : list LinExpr for each argument. shape : tuple The shape of the resulting expression. data : Additional data required by the atom. Returns ------- tuple (LinOp for objective, list of constraints) """ return (lu.reshape(arg_objs[0], shape), [])