Tensor Module

This module contains Tensor class which serves as the base class for more specific Tensors in General Relativity:

class einsteinpy.symbolic.tensor.Tensor(arr, config='ll')

Base Class for Tensor manipulation

Constructor and Initializer

Parameters:
  • arr (ImmutableDenseNDimArray or list) – Sympy Array or multi-dimensional list containing Sympy Expressions
  • config (str) – Configuration of contravariant and covariant indices in tensor. ‘u’ for upper and ‘l’ for lower indices. Defaults to ‘ll’.
Raises:
  • TypeError – Raised when arr is not a list or sympy array
  • TypeError – Raised when config is not of type str or contains characters other than ‘l’ or ‘u’
order

Returns the order of the Tensor

config

Returns the configuration of covariant and contravariant indices

tensor()

Returns the sympy Array

Returns:Sympy Array object
Return type:ImmutableDenseNDimArray
subs(*args)

Substitute the variables/expressions in a Tensor with other sympy variables/expressions.

Parameters:args (one argument or two argument) –
  • two arguments, e.g foo.subs(old, new)
  • one iterable argument, e.g foo.subs([(old1, new1), (old2, new2)]) for multiple substitutions at once.
Returns:Tensor with substituted values
Return type:Tensor
simplify()

Returns a simplified Tensor

Returns:Simplified Tensor
Return type:Tensor