You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: axisangle2matrix.m
    path of file: ./repos/gptoolbox/mesh
    
    the code of the file until where you have to start completion: function R = axisangle2matrix(w,a)
  % AXISANGLE2MATRIX  Conver axis angle rotations into corresponding rotation
  % matrices
  %
  % R = axisangle2matrix(w,a)
  %
  % Inputs:
  %   w  n by 3 list of axis vectors
  %   a  n by 1 list of angles
  % Output:
  %   R  3 by 3 by n array of rotation matrices
  %

  % For now NaNs are not allowed
  assert(~any(isnan(w(:))));
  assert(size(w,1) == size(a,1));
  n = size(w,1);
  assert(size(w,2) == 3);


  % build the rotation matrix
  s = sin(a);
  c = cos(a);
  t = 1 - c;

  w = normalizerow(w);

  x = w(:,1);
  y = w(:,2);
  z = w(:,3);
  R = zeros([3,3,n]);
  R(1,1,:) = t.*x.*x + c;
  R(2,1,:) = t.*y.*x + s.*z;
  R(3,1,:) = t.*z.*x - s.*y;


    
function R = axisangle2matrix(w,a)
  % AXISANGLE2MATRIX  Conver axis angle rotations into corresponding rotation
  % matrices
  %
  % R = axisangle2matrix(w,a)
  %
  % Inputs:
  %   w  n by 3 list of axis vectors
  %   a  n by 1 list of angles
  % Output:
  %   R  3 by 3 by n array of rotation matrices
  %

  % For now NaNs are not allowed
  assert(~any(isnan(w(:))));
  assert(size(w,1) == size(a,1));
  n = size(w,1);
  assert(size(w,2) == 3);


  % build the rotation matrix
  s = sin(a);
  c = cos(a);
  t = 1 - c;

  w = normalizerow(w);

  x = w(:,1);
  y = w(:,2);
  z = w(:,3);
  R = zeros([3,3,n]);
  R(1,1,:) = t.*x.*x + c;
  R(2,1,:) = t.*y.*x + s.*z;
  R(3,1,:) = t.*z.*x - s.*y;

  R(1,2,:) = t.*x.*y - s.*z;
  R(2,2,:) = t.*y.*y + c;
  R(3,2,:) = t.*z.*y + s.*x;

  R(1,3,:) = t.*x.*z + s.*y;
  R(2,3,:) = t.*y.*z - s.*x;
  R(3,3,:) = t.*z.*z + c;

end