transformseq¶
The transformseq module.
- class nutils.transformseq.Transforms(todims, fromdims)¶
Bases:
Singleton
Abstract base class for a sequence of
TransformItem
tuples.This class resembles to some extent a plain
tuple
: the class supports indexing, iterating and has anindex()
method. In addition the class supports theindex_with_tail()
method which can be used to find the index of a transform given the transform plus any number of child transformations.The transforms in this sequence must satisfy the following condition: any transform must not start with any other transform in the same sequence.
- Parameters:
Notes
Subclasses must implement
__getitem__()
,__len__()
andindex_with_tail()
.- abstract __len__(self)¶
Return
len(self)
.
- __getitem__(self, index)¶
Return
self[index]
.
- abstract index_with_tail(self, trans)¶
Return the index of
trans[:n]
and the tailtrans[n:]
.Find the index of a transform in this sequence given the transform plus any number of child transforms. In other words: find
index
such thatself[index] == trans[:n]
for somen
. Note that there is either exactly oneindex
satisfying this condition, or none, due to the restrictions of the transforms in aTransforms
object.- Parameters:
trans (
tuple
ofnutils.transform.TransformItem
objects) – The transform to find up to a possibly empty tail.- Returns:
index (
int
) – The index oftrans
without tail in this sequence.tail (
tuple
ofnutils.transform.TransformItem
objects) – The tail:trans[len(self[index]):]
.
- Raises:
ValueError – if
trans
is not found.
Example
Consider the following plain sequence of two index transforms:
>>> from nutils.transform import Index, SimplexChild >>> transforms = PlainTransforms(((Index(1, 0),), (Index(1, 1),)), 1, 1)
Calling
index_with_tail()
with the first transform gives index0
and no tail:>>> transforms.index_with_tail((Index(1, 0),)) (0, ())
Calling with an additional scale gives:
>>> transforms.index_with_tail((Index(1, 0), SimplexChild(1, 0))) (0, (SimplexChild([0]+[.5]*x0),))
- __iter__(self)¶
Implement
iter(self)
.
- index(self, trans)¶
Return the index of
trans
.- Parameters:
trans (
tuple
ofnutils.transform.TransformItem
objects) –- Returns:
index – The index of
trans
in this sequence.- Return type:
- Raises:
ValueError – if
trans
is not found.
Example
Consider the following plain sequence of two index transforms:
>>> from nutils.transform import Index, SimplexChild >>> transforms = PlainTransforms(((Index(1, 0),), (Index(1, 1),)), 1, 1)
Calling
index()
with the first transform gives index0
:>>> transforms.index((Index(1, 0),)) 0
Calling with an additional scale raises an exception, because the transform is not present in
transforms
.>>> transforms.index((Index(1, 0), SimplexChild(1, 0))) Traceback (most recent call last): ... ValueError: (Index(1, 0), SimplexChild([0]+[.5]*x0)) not in sequence of transforms
- contains(self, trans)¶
Return
trans
inself
.- Parameters:
trans (
tuple
ofnutils.transform.TransformItem
objects) –- Returns:
True
iftrans
is contained in this sequence of transforms, i.e. ifindex()
returns withoutValueError
, otherwiseFalse
.- Return type:
- __contains__(self, trans)¶
Return
trans
inself
.- Parameters:
trans (
tuple
ofnutils.transform.TransformItem
objects) –- Returns:
True
iftrans
is contained in this sequence of transforms, i.e. ifindex()
returns withoutValueError
, otherwiseFalse
.- Return type:
- contains_with_tail(self, trans)¶
Return
trans[:n]
inself
for somen
.- Parameters:
trans (
tuple
ofnutils.transform.TransformItem
objects) –- Returns:
True
if a head oftrans
is contained in this sequence of transforms, i.e. ifindex_with_tail()
returns withoutValueError
, otherwiseFalse
.- Return type:
- refined(self, references)¶
Return the sequence of refined transforms given
references
.- Parameters:
references (
References
) – A sequence of references matching this sequence of transforms.- Returns:
The sequence of refined transforms:
(trans+(ctrans,) for trans, ref in zip(self, references) for ctrans in ref.child_transforms)
- Return type:
- edges(self, references)¶
Return the sequence of edge transforms given
references
.- Parameters:
references (
References
) – A sequence of references matching this sequence of transforms.- Returns:
The sequence of edge transforms:
(trans+(etrans,) for trans, ref in zip(self, references) for etrans in ref.edge_transforms)
- Return type:
- __add__(self, other)¶
Return
self+other
.
- unchain(self)¶
Iterator of unchained
Transforms
items.- Yields:
Transforms
– Unchained items.
- class nutils.transformseq.EmptyTransforms(todims, fromdims)¶
Bases:
Transforms
An empty sequence.
- class nutils.transformseq.PlainTransforms(transforms, todims, fromdims)¶
Bases:
Transforms
A general purpose implementation of
Transforms
.Use this class only if there exists no specific implementation of
Transforms
for the transforms at hand.- Parameters:
transforms (
tuple
ofTransformItem
objects) – The sequence of transforms in canonical order.fromdims (
int
) – The number of dimensions alltransforms
map from.
- class nutils.transformseq.IndexTransforms(ndims, length, offset=0)¶
Bases:
Transforms
A sequence of
nutils.transform.Index
singletons.- Parameters:
ndims (
int
) – Dimension of the transformation.length (
int
) – Length of the sequence.offset (
int
) – The index of the firstnutils.transform.Index
in this sequence.
- class nutils.transformseq.Axis(i, j, mod)¶
Bases:
Singleton
Base class for axes of
StructuredTopology
.
- class nutils.transformseq.StructuredTransforms(root, axes, nrefine)¶
Bases:
Transforms
Transforms sequence for
StructuredTopology
.- Parameters:
root (
TransformItem
) – Root transform of theStructuredTopology
.axes (
tuple
ofAxis
objects) – The axes defining theStructuredTopology
.nrefine (
int
) – Number of structured refinements.
- class nutils.transformseq.MaskedTransforms(parent, indices)¶
Bases:
Transforms
An order preserving subset of another
Transforms
object.- Parameters:
parent (
Transforms
) – The transforms to subset.indices (one-dimensional array of
int
s) – The strict monotonic increasing indices ofparent
transforms to keep.
- class nutils.transformseq.ReorderedTransforms(parent, indices)¶
Bases:
Transforms
A reordered
Transforms
object.- Parameters:
parent (
Transforms
) – The transforms to reorder.indices (one-dimensional array of
int
s) – The new order of the transforms.
- class nutils.transformseq.DerivedTransforms(parent, parent_references, derived_attribute, fromdims)¶
Bases:
Transforms
A sequence of derived transforms.
The derived transforms are ordered first by parent transforms, then by derived transforms, as returned by the reference:
(trans+(ctrans,) for trans, ref in zip(parent, parent_references) for ctrans in getattr(ref, derived_attribute))
- Parameters:
parent (
Transforms
) – The transforms to refine.parent_references (
References
) – The references to use for the refinement.derived_attribute (
str
) – The name of the attribute of anutils.element.Reference
that contains the derived references.fromdims (
int
) – The number of dimensions all transforms in this sequence map from.
- class nutils.transformseq.UniformDerivedTransforms(parent, parent_reference, derived_attribute, fromdims)¶
Bases:
Transforms
A sequence of refined transforms from a uniform sequence of references.
The refined transforms are ordered first by parent transforms, then by derived transforms, as returned by the reference:
(trans+(ctrans,) for trans in parent for ctrans in getattr(parent_reference, derived_attribute))
- Parameters:
parent (
Transforms
) – The transforms to refine.parent_reference (
Reference
) – The reference to use for the refinement.derived_attribute (
str
) – The name of the attribute of anutils.element.Reference
that contains the derived references.fromdims (
int
) – The number of dimensions all transforms in this sequence map from.
- class nutils.transformseq.ChainedTransforms(items)¶
Bases:
Transforms
A sequence of chained
Transforms
objects.- Parameters:
items (
tuple
ofTransforms
objects) – TheTransforms
objects to chain.
- nutils.transformseq.chain(items, todims, fromdims)¶
Return the chained transforms sequence of
items
.- Parameters:
items (iterable of
Transforms
objects) – TheTransforms
objects to chain.fromdims (
int
) – The number of dimensions all transforms in this sequence map from.
- Returns:
The chained transforms.
- Return type: