* add eye op,test=document_preview test=develop

* fix the API.spec, test=develop

* fix the document, test=document_preview test=develop

* add unitest for CI coverage, test=develop

* add trilinear interp. test=develop

* fix unittest. test=develop

* add python api and test_layers. test=develop

* refine API.spec. test=develop

* fix format. test=develop

* add python API test. test=develop

* format code. test=develop

* refine code strcuture. test=develop

* fix format

* fix doc. test=develop

* fix converage. test=develop

* fix format. test=develop

* update roi doc in roi_pool and roi_align, test=develop

* fix overflow by int32 mul test=develop

* fix reference nullptr

* fix codestyle test=develop

* modify to point in ContextProjectFunctor test=develop

* modify to point in ContextProjectFunctor test=develop

* modify . to -> test=develop

* add var_conv_2d op test=develop

* edit api.spec test=develop

* ignore unittest if with_mkl=off test=develop

* fix python3 division test=develop

* fix ignore unittest bug test=develop

* remove useless code test=develop

* modify api.spec test=develop

* modify default_grad.spec test=develop

* fix profiler doc error, test=develop

* update API.spec, test=develop

* fix g_param shape mismatch in WeightNormParamAttr

* add comment to show why insert reshape in startup_program
test=develop

* update exe.run

* test=develop test=document_preview

* Update API.spec

* test=develop
Add the op of unique_with_counts, the op is calc the unqiue input of data, and output the corresponding indices and count of data.

* test=develop
Check the input and dtype in the op of unique_with_counts

* test=develop
test=document_preview
update the API.spec for `unique_with_counts`, at the same time, optimize the python api in the op of `unique_with_count`

* test=develop
test=document_preview
Fix some python api problem in the op of `unique_with_counts`, and change the error messsage in this op.

* Fix some API problem in the op of `unique_with_counts`
test=develop
test=document_preview

* test=develop
test=document_preview
Fix the api sample of op `unique_with_counts`, and update api.spec

* support center loss
* change tensor copy  api to high level api tensorcopy

* test=develop rewrite the center_loss cuda_kernel to make it faster
and add document of the center loss api,also update test function

* test=document_preview test=develop
update document of center loss

* test=document_preview test=develop
modify API.spec modify test code remove nouse const_cast

Update conv2d transpose link

test=develop

* replace link

* update api.spec

* fix mistake

* fix logical APIs

test=develop

test=document_preview

* fix isfinite

* update matmul comments

* update API.spec

test=document_preview

test=develop

* update API.spec

test=document_preview

test=develop

* update API.spec

test=document_preview

test=develop

* Make lod reset op support for append lod level.

* Fix API.spec
test=develop

* Fix unitest.
test=develop

* Add python api for lod append.
test=develop

* Fix API.spec
test=develop

* Fix format of doc.
test=develop

* Fix unitest.
test=develop

* Fix doc.
test=develop

Modify auc doc. Add output variable description, previously was the scalar type, now changed to the tuple type.test=develop (#18771)

* supports distributed classification training
* update API.spec
* fix evenly division in python3
* change "index_range" to "index_num" in shard_index operator
test=document_preview
test=develop

* fix clip_by_norm doc, test=develop

* remove ctr reader, all functions are satisfied in dataset

remove dygraph.enable from __all__
hidden dygraph. profiler
add doc to dygraph. no_grad

* fix transform matrix bug, test=develop

* modify API.spec

* add_distributions_of_normal_and_uniform

* paddle/fluid/API.spec

* modify API.spec

* modified paddle/fluid/API.spec, test=develop

* modify paddle/fluid/API.spec, test=develop

* modify paddle/fluid/API.spec, test=develop

* fix some comment, test=develop

* modify API.spec, test=develop

* add comment for init function, modify hard code, test=develop

* modify API.spec, test=develop

* modify API.spec, test=develop

* make unit test function shorter, test=develop

* modify paddle/fluid/API.spec

* make it support float/int learning as input.

* test=develop
support Tensor input for chunk_eval op

* test=develop
fix testcase for chunk_eval op

* test=develop
fix typos in nn.py

* fix the api.spec file does not get the class comment problem

* cat new.spec

* check api.spec

* test=develop

* modify roi_perspective_transform_op to output mask and transform matrix

* modify comment

* modify comment

* modify API.spec

* update API.spec

* remove no use header, test=develop

* resolve conflict

* update api format
test=develop

* update API.spec
test=develop

test=develop

* test=develop, add some comments for Program.clone

* test=develop, add API.spec

* test=develop, refine comments

* refine Program doc and clone doc

* test=develop, refine doc

*  add cuda_is_available
test=develop

* Fix api.spec
test=develop

* fix api doc
test=develop

Fix dygraph show style for FluidDoc.