本文整理汇总了Python中sage.tensor.modules.free_module_tensor.FreeModuleTensor.set_comp方法的典型用法代码示例。如果您正苦于以下问题：Python FreeModuleTensor.set_comp方法的具体用法？Python FreeModuleTensor.set_comp怎么用？Python FreeModuleTensor.set_comp使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类sage.tensor.modules.free_module_tensor.FreeModuleTensor的用法示例。
在下文中一共展示了FreeModuleTensor.set_comp方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: set_comp
# 需要导入模块: from sage.tensor.modules.free_module_tensor import FreeModuleTensor [as 别名]
# 或者: from sage.tensor.modules.free_module_tensor.FreeModuleTensor import set_comp [as 别名]
def set_comp(self, basis=None):
r"""
Return the components of ``self`` w.r.t. a given module basis for
assignment.
The components with respect to other bases are deleted, in order to
avoid any inconsistency. To keep them, use the method :meth:`add_comp`
instead.
INPUT:
- ``basis`` -- (default: ``None``) basis in which the components are
defined; if none is provided, the components are assumed to refer to
the module's default basis
OUTPUT:
- components in the given basis, as an instance of the
class :class:`~sage.tensor.modules.comp.Components`; if such
components did not exist previously, they are created.
EXAMPLES:
Setting the components of an automorphism of a rank-3 free
`\ZZ`-module::
sage: M = FiniteRankFreeModule(ZZ, 3, name='M')
sage: e = M.basis('e')
sage: a = M.automorphism(name='a')
sage: a.set_comp(e)
2-indices components w.r.t. Basis (e_0,e_1,e_2) on the Rank-3 free
module M over the Integer Ring
sage: a.set_comp(e)[:] = [[1,0,0],[0,1,2],[0,1,3]]
sage: a.matrix(e)
[1 0 0]
[0 1 2]
[0 1 3]
Since ``e`` is the module's default basis, one has::
sage: a.set_comp() is a.set_comp(e)
True
The method :meth:`set_comp` can be used to modify a single component::
sage: a.set_comp(e)[0,0] = -1
sage: a.matrix(e)
[-1 0 0]
[ 0 1 2]
[ 0 1 3]
A short cut to :meth:`set_comp` is the bracket operator, with the basis
as first argument::
sage: a[e,:] = [[1,0,0],[0,-1,2],[0,1,-3]]
sage: a.matrix(e)
[ 1 0 0]
[ 0 -1 2]
[ 0 1 -3]
sage: a[e,0,0] = -1
sage: a.matrix(e)
[-1 0 0]
[ 0 -1 2]
[ 0 1 -3]
The call to :meth:`set_comp` erases the components previously defined
in other bases; to keep them, use the method :meth:`add_comp` instead::
sage: f = M.basis('f', from_family=(-e[0], 3*e[1]+4*e[2],
....: 5*e[1]+7*e[2])) ; f
Basis (f_0,f_1,f_2) on the Rank-3 free module M over the Integer
Ring
sage: a._components
{Basis (e_0,e_1,e_2) on the Rank-3 free module M over the Integer
Ring: 2-indices components w.r.t. Basis (e_0,e_1,e_2) on the
Rank-3 free module M over the Integer Ring}
sage: a.set_comp(f)[:] = [[-1,0,0], [0,1,0], [0,0,-1]]
The components w.r.t. basis ``e`` have been erased::
sage: a._components
{Basis (f_0,f_1,f_2) on the Rank-3 free module M over the Integer
Ring: 2-indices components w.r.t. Basis (f_0,f_1,f_2) on the
Rank-3 free module M over the Integer Ring}
Of course, they can be computed from those in basis ``f`` by means of
a change-of-basis formula, via the method :meth:`comp` or
:meth:`matrix`::
sage: a.matrix(e)
[ -1 0 0]
[ 0 41 -30]
[ 0 56 -41]
For the identity map, it is not permitted to set components::
sage: id = M.identity_map()
sage: id.set_comp(e)
Traceback (most recent call last):
...
#.........这里部分代码省略.........