class_docstr: Torch autograd function for matrix logarithm.
  
  Implementation based on:
  https://github.com/pytorch/pytorch/issues/9983#issuecomment-891777620
class_docstr_tok: ["Torch","autograd","function","for","matrix","logarithm",".","Implementation","based","on",":","https",":","\/\/github.com\/pytorch\/pytorch\/issues\/9983","#","issuecomment-891777620"]
docstr: Apply matrix logarithm to a tensor.
docstr_tok: ["Apply","matrix","logarithm","to","a","tensor","."]
code: def forward(ctx, tensor):
      """Apply matrix logarithm to a tensor."""
      ctx.save_for_backward(tensor)
      return _Logm._logm(tensor)
  
file_path: geomstats/geomstats/_backend/pytorch/linalg.py
imports: import numpy
  import scipy
  import torch
  from .._backend_config import np_atol
  from ..numpy import linalg
  from ._dtype import _cast_out_to_input_dtype
label_desc: Use image node_id 2 for calling the _Logm obj's underlying member method code with example usage: obj.forward(ctx, tensor) and returns: _Logm