pymor.vectorarrays package¶
Submodules¶
block module¶
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class
pymor.vectorarrays.block.BlockVectorArray(blocks, space)[source]¶ Bases:
pymor.vectorarrays.interfaces.VectorArrayInterfaceVectorArraywhere each vector is a direct sum of sub-vectors.Given a list of equal length
VectorArraysblocks, thisVectorArrayrepresents the direct sums of the vectors contained in the arrays. The associatedVectorSpaceInterfaceisBlockVectorSpace.BlockVectorArraycan be used in conjunction withBlockOperator.Methods
Attributes
BlockVectorArraydata,imag,num_blocks,realVectorArrayInterfacedim,is_view,spaceBasicInterfacelogger,logging_disabled,name,uid
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class
pymor.vectorarrays.block.BlockVectorArrayView(base, ind)[source]¶ Bases:
pymor.vectorarrays.block.BlockVectorArrayMethods
Attributes
BlockVectorArrayViewis_viewBlockVectorArraydata,imag,num_blocks,realVectorArrayInterfacedim,spaceBasicInterfacelogger,logging_disabled,name,uid
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class
pymor.vectorarrays.block.BlockVectorSpace(subspaces, id_=None)[source]¶ Bases:
pymor.vectorarrays.interfaces.VectorSpaceInterfaceVectorSpaceInterfaceofBlockVectorArrays.A
BlockVectorSpaceis defined by theVectorSpacesof the individual subblocks which constitute a given array. In particular for a given :class`BlockVectorArray`U, we have the identity(U.blocks[0].space, U.blocks[1].space, ..., U.blocks[-1].space) == U.space.
Parameters
- subspaces
- The tuple defined above.
constructions module¶
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pymor.vectorarrays.constructions.cat_arrays(vector_arrays)[source]¶ Return a new
VectorArraywhich is a concatenation of the arrays invector_arrays.
interfaces module¶
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class
pymor.vectorarrays.interfaces.VectorArrayInterface[source]¶ Bases:
pymor.core.interfaces.BasicInterfaceInterface for vector arrays.
A vector array should be thought of as a list of (possibly high-dimensional) vectors. While the vectors themselves will be inaccessible in general (e.g. because they are managed by an external PDE solver code), operations on the vectors like addition can be performed via this interface.
It is assumed that the number of vectors is small enough such that scalar data associated to each vector can be handled on the Python side. As such, methods like
l2_normorgramianwill always returnNumPy arrays.An implementation of the
VectorArrayInterfaceviaNumPy arraysis given byNumpyVectorArray. In general, it is the implementors decision how memory is allocated internally (e.g. continuous block of memory vs. list of pointers to the individual vectors.) Thus, no general assumptions can be made on the costs of operations like appending to or removing vectors from the array. As a hint for ‘continuous block of memory’ implementations,zerosprovides areservekeyword argument which allows to specify to what size the array is assumed to grow.As with
NumPy array,VectorArrayscan be indexed with numbers, slices and lists or one-dimensionalNumPy arrays. Indexing will always return a newVectorArraywhich acts as a view into the original data. Thus, if the indexed array is modified viascaloraxpy, the vectors in the original array will be changed. Indices may be negative, in which case the vector is selected by counting from the end of the array. Moreover indices can be repeated, in which case the corresponding vector is selected several times. The resulting view will be immutable, however.Note
It is disallowed to append vectors to a
VectorArrayview or to remove vectors from it. Removing vectors from an array with existing views will lead to undefined behavior of these views. As such, it is generally advisable to make acopyof a view for long term storage. Sincecopyhas copy-on-write semantics, this will usually cause little overhead.Methods
Attributes
VectorArrayInterfacedata,dim,is_view,spaceBasicInterfacelogger,logging_disabled,name,uid-
data¶ Implementors can provide a
dataproperty which returns aNumPy arrayof shape(len(v), v.dim)containing the data stored in the array. Access should be assumed to be slow and is mainly intended for debugging / visualization purposes or to once transfer data to pyMOR and further process it using NumPy. In the case ofNumpyVectorArray, an actual view of the internally usedNumPy arrayis returned, so changing it, will alter theVectorArray. Thus, you cannot assume to own the data returned to you, in general.
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dim¶ The dimension of the vectors in the array.
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is_view¶ Trueif the array is a view obtained by indexing another array.
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space¶ The
VectorSpaceInterfacethe array belongs to.
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__add__(other)[source]¶ The pairwise sum of two
VectorArrays.
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__getitem__(ind)[source]¶ Return a
VectorArrayview onto a subset of the vectors in the array.
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__iadd__(other)[source]¶ In-place pairwise addition of
VectorArrays.
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__isub__(other)[source]¶ In-place pairwise difference of
VectorArrays.
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__radd__(other)¶ The pairwise sum of two
VectorArrays.
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__rmul__(other)¶ Product by a scalar.
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__sub__(other)[source]¶ The pairwise difference of two
VectorArrays.
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amax()[source]¶ The maximum absolute value of the vectors contained in the array.
Returns
- max_ind
NumPy arraycontaining for each vector an index at which the maximum is attained.- max_val
NumPy arraycontaining for each vector the maximum absolute value of its components.
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append(other, remove_from_other=False)[source]¶ Append vectors to the array.
Parameters
- other
- A
VectorArraycontaining the vectors to be appended. - remove_from_other
- If
True, the appended vectors are removed fromother. For list-like implementations this can be used to prevent unnecessary copies of the involved vectors.
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axpy(alpha, x)[source]¶ BLAS AXPY operation.
This method forms the sum
self = alpha*x + self
If the length of
xis 1, the samexvector is used for all vectors inself. Otherwise, the lengths ofselfandxhave to agree. Ifalphais a scalar, eachxvector is multiplied with the same factoralpha. Otherwise,alphahas to be a one-dimensionalNumPy arrayof the same length asselfcontaining the coefficients for eachxvector.Parameters
- alpha
- The scalar coefficient or one-dimensional
NumPy arrayof coefficients with which the vectors inxare multiplied. - x
- A
VectorArraycontaining the x-summands.
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check_ind(ind)[source]¶ Check if
indis an admissable list of indices in the sense of the class documentation.
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check_ind_unique(ind)[source]¶ Check if
indis an admissable list of non-repeated indices in the sense of the class documentation.
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components(component_indices)[source]¶ Extract components of the vectors contained in the array.
Parameters
- component_indices
- List or 1D
NumPy arrayof indices of the vector components that are to be returned.
Returns
A
NumPy arrayresultsuch thatresult[i, j]is thecomponent_indices[j]-th component of thei-th vector of the array.
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copy(deep=False)[source]¶ Returns a copy of a subarray.
All
VectorArrayimplementations in pyMOR have copy-on-write semantics: if not specified otherwise by settingdeeptoTrue, the returned copy will hold a handle to the same array data as the original array, and a deep copy of the data will only be performed when one of the arrays is modified.Note that for
NumpyVectorArray, a deep copy is always performed when only some vectors in the array are copied.Parameters
- deep
- Ensure that an actual copy of the array data is made (see above).
Returns
A copy of the
VectorArray.
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dot(other)[source]¶ Returns the inner products between
VectorArrayelements.Parameters
- other
- A
VectorArraycontaining the second factors.
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empty(reserve=0)[source]¶ Create an empty
VectorArrayof the sameVectorSpaceInterface.This is a shorthand for
self.space.zeros(0, reserve).Parameters
- reserve
- Hint for the backend to which length the array will grow.
Returns
An empty
VectorArray.
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l1_norm()[source]¶ The l1-norms of the vectors contained in the array.
Returns
A
NumPy arrayresultsuch thatresult[i]contains the norm ofself[i].
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l2_norm()[source]¶ The l2-norms of the vectors contained in the array.
Returns
A
NumPy arrayresultsuch thatresult[i]contains the norm ofself[i].
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l2_norm2()[source]¶ The squared l2-norms of the vectors contained in the array.
Returns
A
NumPy arrayresultsuch thatresult[i]contains the norm ofself[i].
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lincomb(coefficients)[source]¶ Returns linear combinations of the vectors contained in the array.
Parameters
- coefficients
- A
NumPy arrayof dimension 1 or 2 containing the linear coefficients.coefficients.shape[-1]has to agree withlen(self).
Returns
A
VectorArrayresultsuch thatresult[i] = ∑ self[j] * coefficients[i,j]in case
coefficientsis of dimension 2, otherwiselen(result) == 1andresult[0] = ∑ self[j] * coefficients[j].
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normalize_ind(ind)[source]¶ Normalize given indices such that they are independent of the array length.
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pairwise_dot(other)[source]¶ Returns the pairwise inner products between
VectorArrayelements.Parameters
- other
- A
VectorArraycontaining the second factors.
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scal(alpha)[source]¶ BLAS SCAL operation (in-place scalar multiplication).
This method calculates
self = alpha*self
If
alphais a scalar, each vector is multiplied by this scalar. Otherwise,alphahas to be a one-dimensionalNumPy arrayof the same length asselfcontaining the factors for each vector.Parameters
- alpha
- The scalar coefficient or one-dimensional
NumPy arrayof coefficients with which the vectors inselfare multiplied.
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sup_norm()[source]¶ The l-infinity–norms of the vectors contained in the array.
Returns
A
NumPy arrayresultsuch thatresult[i]contains the norm ofself[i].
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zeros(count=1, reserve=0)[source]¶ Create a
VectorArrayof null vectors of the sameVectorSpaceInterface.This is a shorthand for
self.space.zeros(count, reserve).Parameters
- count
- The number of vectors.
- reserve
- Hint for the backend to which length the array will grow.
Returns
A
VectorArraycontainingcountvectors whith each component zero.
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class
pymor.vectorarrays.interfaces.VectorSpaceInterface[source]¶ Bases:
pymor.core.interfaces.ImmutableInterfaceClass describing a vector space.
Vector spaces act as factories for
VectorArraysof vectors contained in them. As such, they hold all data necessary to createVectorArraysof a given type (e.g. the dimension of the vectors, or a socket for communication with an external PDE solver).New
VectorArraysof null vectors are created viazeros. Themake_arraymethod builds a newVectorArrayfrom given raw data of the underlying linear algebra backend (e.g. aNumPy arrayin the case ofNumpyVectorSpace). Some vector spaces can create newVectorArraysfrom a givenNumPy arrayvia thefrom_datamethod.Each vector space has a string
idto distinguish mathematically different spaces appearing in the formulation of a given problem.Vector spaces can be compared for equality via the
==and!=operators. To test if a givenVectorArrayis an element of the space, theinoperator can be used.Methods
Attributes
VectorSpaceInterfacedim,id,is_scalarImmutableInterfaceadd_with_arguments,sid,sid_ignore,with_argumentsBasicInterfacelogger,logging_disabled,name,uid-
id¶ None, or a string describing the mathematical identity of the vector space (for instance to distinguish different components in an equation system).
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dim¶ The dimension (number of degrees of freedom) of the vectors contained in the space.
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is_scalar¶ Equivalent to
isinstance(space, NumpyVectorSpace) and space.dim == 1.
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empty(reserve=0)[source]¶ Create an empty
VectorArrayThis is a shorthand for
self.zeros(0, reserve).Parameters
- reserve
- Hint for the backend to which length the array will grow.
Returns
An empty
VectorArray.
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from_data(data)[source]¶ Create a
VectorArrayfrom aNumPy arrayNote that this method will not be supported by all vector space implementations.
Parameters
- data
NumPyarray.
Returns
A
VectorArraywithdataas data.
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make_array(*args, **kwargs)[source]¶ Create a
VectorArrayfrom raw data.This method is used in the implementation of
OperatorsandDiscretizationsto create newVectorArraysfrom raw data of the underlying solver backends. The ownership of the data is transferred to the newly created array.The exact signature of this method depends on the wrapped solver backend.
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zeros(count=1, reserve=0)[source]¶ Create a
VectorArrayof null vectorsParameters
- count
- The number of vectors.
- reserve
- Hint for the backend to which length the array will grow.
Returns
A
VectorArraycontainingcountvectors with each component zero.
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list module¶
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class
pymor.vectorarrays.list.CopyOnWriteVector[source]¶ Bases:
pymor.vectorarrays.list.VectorInterfaceMethods
CopyOnWriteVectoraxpy,copy,from_instance,scalVectorInterfaceamax,components,dot,l1_norm,l2_norm,l2_norm2,sup_normBasicInterfacedisable_logging,enable_logging,has_interface_name,implementor_names,implementorsAttributes
BasicInterfacelogger,logging_disabled,name,uid
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class
pymor.vectorarrays.list.ListVectorArray(vectors, space)[source]¶ Bases:
pymor.vectorarrays.interfaces.VectorArrayInterfaceVectorArrayimplemented as a Python list of vectors.This
VectorArrayimplementation is the first choice when creating pyMOR wrappers for external solvers which are based on single vector objects. In order to do so, a wrapping subclass ofVectorInterfacehas to be provided on which the implementation ofListVectorArraywill operate. The associatedVectorSpaceInterfaceis a subclass ofListVectorSpace.For an example, see
NumpyVector,NumpyListVectorSpaceorFenicsVector,FenicsVectorSpace.Methods
Attributes
ListVectorArraydataVectorArrayInterfacedim,is_view,spaceBasicInterfacelogger,logging_disabled,name,uid
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class
pymor.vectorarrays.list.ListVectorArrayView(base, ind)[source]¶ Bases:
pymor.vectorarrays.list.ListVectorArrayMethods
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class
pymor.vectorarrays.list.ListVectorSpace[source]¶ Bases:
pymor.vectorarrays.interfaces.VectorSpaceInterfaceVectorSpaceInterfaceofListVectorArrays.Methods
ListVectorSpacefrom_data,make_array,make_vector,space_from_dim,space_from_vector_obj,vector_from_data,zero_vector,zerosVectorSpaceInterfaceemptyImmutableInterfacegenerate_sid,with_,__setattr__BasicInterfacedisable_logging,enable_logging,has_interface_name,implementor_names,implementors
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class
pymor.vectorarrays.list.NumpyListVectorSpace(dim, id_=None)[source]¶ Bases:
pymor.vectorarrays.list.ListVectorSpaceMethods
NumpyListVectorSpacemake_vector,space_from_dim,space_from_vector_obj,vector_from_data,zero_vectorListVectorSpacefrom_data,make_array,zerosVectorSpaceInterfaceemptyImmutableInterfacegenerate_sid,with_,__setattr__BasicInterfacedisable_logging,enable_logging,has_interface_name,implementor_names,implementors
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class
pymor.vectorarrays.list.NumpyVector(array)[source]¶ Bases:
pymor.vectorarrays.list.CopyOnWriteVectorVector stored in a NumPy 1D-array.
Methods
NumpyVectoramax,components,dot,from_instance,l1_norm,l2_norm,l2_norm2CopyOnWriteVectoraxpy,copy,scalVectorInterfacesup_normBasicInterfacedisable_logging,enable_logging,has_interface_name,implementor_names,implementorsAttributes
NumpyVectordata,dimBasicInterfacelogger,logging_disabled,name,uid
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class
pymor.vectorarrays.list.VectorInterface[source]¶ Bases:
pymor.core.interfaces.BasicInterfaceInterface for vectors used in conjunction with
ListVectorArray.This interface must be staisfied by the individual entries of the vector
listmanaged byListVectorArray. All interface methods have a direct counterpart in theVectorArrayinterface.Methods
VectorInterfaceamax,axpy,components,copy,dot,l1_norm,l2_norm,l2_norm2,scal,sup_normBasicInterfacedisable_logging,enable_logging,has_interface_name,implementor_names,implementorsAttributes
BasicInterfacelogger,logging_disabled,name,uid
mpi module¶
Wrapper classes for building MPI distributed VectorArrays.
This module contains several wrapper classes which allow to
transform single rank VectorArrays into MPI distributed
VectorArrays which can be used on rank 0 like ordinary
VectorArrays.
The implementations are based on the event loop provided
by pymor.tools.mpi.
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class
pymor.vectorarrays.mpi.MPIVectorArray(obj_id, space)[source]¶ Bases:
pymor.vectorarrays.interfaces.VectorArrayInterfaceMPI distributed
VectorArray.Given a local
VectorArrayon each MPI rank, this wrapper class uses the event loop frompymor.tools.mpito build a global MPI distributed vector array from these local arrays.Instances of
MPIVectorArraycan be used on rank 0 like any other (non-distributed)VectorArray.Note, however, that the implementation of the local VectorArrays needs to be MPI aware. For instance,
cls.dotmust perform the needed MPI communication to sum up the local inner products and return the sums on rank 0.Default implementations for all communication requiring interface methods are provided by
MPIVectorArrayAutoComm(also seeMPIVectorArrayNoComm).Note that resource cleanup is handled by
object.__del__. Please be aware of the peculiarities of destructors in Python!The associated
VectorSpaceInterfaceisMPIVectorSpace.Methods
Attributes
VectorArrayInterfacedata,dim,is_view,spaceBasicInterfacelogger,logging_disabled,name,uid
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class
pymor.vectorarrays.mpi.MPIVectorArrayAutoComm(obj_id, space)[source]¶ Bases:
pymor.vectorarrays.mpi.MPIVectorArrayMPI distributed
VectorArray.This is a subclass of
MPIVectorArraywhich provides default implementations for all communication requiring interface methods for the case when the wrapped array is not MPI aware.Note, however, that depending on the discretization these default implementations might lead to wrong results (for instance in the presence of shared DOFs).
The associated
VectorSpaceInterfaceisMPIVectorSpaceAutoComm.Methods
Attributes
VectorArrayInterfacedata,dim,is_view,spaceBasicInterfacelogger,logging_disabled,name,uid
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class
pymor.vectorarrays.mpi.MPIVectorArrayNoComm(obj_id, space)[source]¶ Bases:
pymor.vectorarrays.mpi.MPIVectorArrayMPI distributed
VectorArray.This is a subclass of
MPIVectorArraywhich overrides all communication requiring interface methods to raiseNotImplementedError.This is mainly useful as a security measure when wrapping arrays for which simply calling the respective method on the wrapped arrays would lead to wrong results and
MPIVectorArrayAutoCommcannot be used either (for instance in the presence of shared DOFs).The associated
VectorSpaceInterfaceisMPIVectorSpaceNoComm.Methods
Attributes
VectorArrayInterfacedata,dim,is_view,spaceBasicInterfacelogger,logging_disabled,name,uid
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class
pymor.vectorarrays.mpi.MPIVectorSpace(local_spaces)[source]¶ Bases:
pymor.vectorarrays.interfaces.VectorSpaceInterfaceVectorSpaceInterfaceofMPIVectorArrays.Parameters
- local_spaces
tupleof the differentVectorSpacesof the localVectorArrayson the MPI ranks. Alternatively, the length oflocal_spacesmay be 1, in which case the sameVectorSpaceInterfaceis assumed for all ranks.
Methods
Attributes
MPIVectorSpacearray_type,dimVectorSpaceInterfaceid,is_scalarImmutableInterfaceadd_with_arguments,sid,sid_ignore,with_argumentsBasicInterfacelogger,logging_disabled,name,uid-
array_type¶ alias of
MPIVectorArray
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make_array(obj_id)[source]¶ Create array from rank-local
VectorArrayinstances.Parameters
- obj_id
ObjectIdof the MPI distributed instances ofclswrapped by this array.
Returns
The newly created : class:
MPIVectorArray.
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class
pymor.vectorarrays.mpi.MPIVectorSpaceAutoComm(local_spaces)[source]¶ Bases:
pymor.vectorarrays.mpi.MPIVectorSpaceVectorSpaceInterfaceforMPIVectorArrayAutoComm.Methods
Attributes
MPIVectorSpaceAutoCommarray_type,dimVectorSpaceInterfaceid,is_scalarImmutableInterfaceadd_with_arguments,sid,sid_ignore,with_argumentsBasicInterfacelogger,logging_disabled,name,uid-
array_type¶ alias of
MPIVectorArrayAutoComm
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-
class
pymor.vectorarrays.mpi.MPIVectorSpaceNoComm(local_spaces)[source]¶ Bases:
pymor.vectorarrays.mpi.MPIVectorSpaceVectorSpaceInterfaceforMPIVectorArrayNoComm.Methods
Attributes
MPIVectorSpaceNoCommarray_type,dimVectorSpaceInterfaceid,is_scalarImmutableInterfaceadd_with_arguments,sid,sid_ignore,with_argumentsBasicInterfacelogger,logging_disabled,name,uid-
array_type¶ alias of
MPIVectorArrayNoComm
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numpy module¶
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class
pymor.vectorarrays.numpy.NumpyVectorArray(array, space)[source]¶ Bases:
pymor.vectorarrays.interfaces.VectorArrayInterfaceVectorArrayimplementation viaNumPy arrays.This is the default
VectorArraytype used by allOperatorsin pyMOR’s discretization toolkit. Moreover, all reducedOperatorsare based onNumpyVectorArray.This class is just a thin wrapper around the underlying
NumPy array. Thus, while operations likeaxpyordotwill be quite efficient, removing or appending vectors will be costly.The associated
VectorSpaceInterfaceisNumpyVectorSpace.Methods
Attributes
NumpyVectorArraydata,imag,realVectorArrayInterfacedim,is_view,spaceBasicInterfacelogger,logging_disabled,name,uid
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class
pymor.vectorarrays.numpy.NumpyVectorArrayView(array, ind)[source]¶ Bases:
pymor.vectorarrays.numpy.NumpyVectorArrayMethods
Attributes
NumpyVectorArrayViewdata,is_viewNumpyVectorArrayimag,realVectorArrayInterfacedim,spaceBasicInterfacelogger,logging_disabled,name,uid
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class
pymor.vectorarrays.numpy.NumpyVectorSpace(dim, id_=None)[source]¶ Bases:
pymor.vectorarrays.interfaces.VectorSpaceInterfaceVectorSpaceInterfaceofNumpyVectorArrays.Parameters
- dim
- The dimension of the vectors contained in the space.
- id
- See
id.