class_docstr: Linear vector function and its derivatives.
  
  Defines a linear function F = A x, where x is n-dimensional vector and
  A is m-by-n matrix. The Jacobian is constant and equals to A. The Hessian
  is identically zero and it is returned as a csr matrix.
class_docstr_tok: ["Linear","vector","function","and","its","derivatives",".","Defines","a","linear","function","F","=","A","x",",","where","x","is","n-dimensional","vector","and","A","is","m-by-n","matrix",".","The","Jacobian","is","constant","and","equals","to","A",".","The","Hessian","is","identically","zero","and","it","is","returned","as","a","csr","matrix","."]
code: def jac(self, x):
      self._update_x(x)
      return self.J
  
imports: from __future__ import division, print_function, absolute_import
  import numpy
  import scipy.sparse
  from ._numdiff import approx_derivative, group_columns
  from ._hessian_update_strategy import HessianUpdateStrategy
  from scipy.sparse.linalg import LinearOperator
label_desc: Use image node_id 4 for calling the LinearVectorFunction obj's underlying member method code with example usage: obj.jac(x) and returns: self