%EYE   Identity tensor.
%   EYE(A) creates a identity tensor with the specification of A.
%   Same dimensionality and sizes of images. The tensor at each pixel
%   is 1 on the diagonal, and 0 off the diagonal.

% (c)2017, Cris Luengo.
% Based on original DIPlib code: (c)1995-2014, Delft University of Technology.
% Based on original DIPimage code: (c)1999-2014, Delft University of Technology.
%
% Licensed under the Apache License, Version 2.0 (the "License");
% you may not use this file except in compliance with the License.
% You may obtain a copy of the License at
%
%    http://www.apache.org/licenses/LICENSE-2.0
%
% Unless required by applicable law or agreed to in writing, software
% distributed under the License is distributed on an "AS IS" BASIS,
% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
% See the License for the specific language governing permissions and
% limitations under the License.

function out = eye(in)
s = tensorsize(in)
if s(1)~=s(2)
   error('The input tensor must be square');
end
out = newtensorim(s(1),imsize(in));
out.Data(:) = 1;
out.TensorShape = 'diagonal matrix';
