[2064]: Add stochastic sampler (sample_dpmpp_sde) (#3020)

* [2064]: Add stochastic sampler

* [2064]: Add stochastic sampler

* [2064]: Add stochastic sampler

* [2064]: Add stochastic sampler

* [2064]: Add stochastic sampler

* [2064]: Add stochastic sampler

* [2064]: Add stochastic sampler

* Review comments

* [Review comment]: Add is_torchsde_available()

* [Review comment]: Test and docs

* [Review comment]

* [Review comment]

* [Review comment]

* [Review comment]

* [Review comment]

---------

Co-authored-by: njindal <[email protected]>

Author: nipunjindal

docs/source/en/_toctree.yml

@@ -266,6 +266,8 @@
       title: VP-SDE
     - local: api/schedulers/vq_diffusion
       title: VQDiffusionScheduler
+    - local: api/schedulers/dpm_sde
+      title: DPMSolverSDEScheduler
     title: Schedulers
   - sections:
     - local: api/experimental/rl

docs/source/en/api/schedulers/dpm_sde.mdx

@@ -0,0 +1,23 @@
+<!--Copyright 2023 The HuggingFace Team. All rights reserved.
+
+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.
+-->
+
+# DPM Stochastic Scheduler inspired by Karras et. al paper
+
+## Overview
+
+Inspired by Stochastic Sampler from [Karras et. al](https://arxiv.org/abs/2206.00364).
+Scheduler ported from @crowsonkb's https://github.com/crowsonkb/k-diffusion library:
+
+All credit for making this scheduler work goes to [Katherine Crowson](https://github.com/crowsonkb/)
+
+## DPMSolverSDEScheduler
+[[autodoc]] DPMSolverSDEScheduler

src/diffusers/__init__.py

@@ -12,6 +12,7 @@
     is_onnx_available,
     is_scipy_available,
     is_torch_available,
+    is_torchsde_available,
     is_transformers_available,
     is_transformers_version,
     is_unidecode_available,
@@ -102,6 +103,13 @@
 else:
     from .schedulers import LMSDiscreteScheduler
 
+try:
+    if not (is_torch_available() and is_torchsde_available()):
+        raise OptionalDependencyNotAvailable()
+except OptionalDependencyNotAvailable:
+    from .utils.dummy_torch_and_torchsde_objects import *  # noqa F403
+else:
+    from .schedulers import DPMSolverSDEScheduler
 
 try:
     if not (is_torch_available() and is_transformers_available()):

src/diffusers/schedulers/__init__.py

@@ -13,7 +13,13 @@
 # limitations under the License.
 
 
-from ..utils import OptionalDependencyNotAvailable, is_flax_available, is_scipy_available, is_torch_available
+from ..utils import (
+    OptionalDependencyNotAvailable,
+    is_flax_available,
+    is_scipy_available,
+    is_torch_available,
+    is_torchsde_available,
+)
 
 
 try:
@@ -72,3 +78,11 @@
     from ..utils.dummy_torch_and_scipy_objects import *  # noqa F403
 else:
     from .scheduling_lms_discrete import LMSDiscreteScheduler
+
+try:
+    if not (is_torch_available() and is_torchsde_available()):
+        raise OptionalDependencyNotAvailable()
+except OptionalDependencyNotAvailable:
+    from ..utils.dummy_torch_and_torchsde_objects import *  # noqa F403
+else:
+    from .scheduling_dpmsolver_sde import DPMSolverSDEScheduler