[Example] Mix algorithm with VLM

examples/grpo_vlm/vlm.yaml

@@ -21,7 +21,7 @@ buffer:
     taskset:
       name: geometry3k
       storage_type: file
-      path: hiyouga/geometry3k
+      path: ${oc.env:TRINITY_TASKSET_PATH,hiyouga/geometry3k}
       subset_name: 'default'
       split: 'train'
       format:

examples/mix_chord/mix_chord.yaml

@@ -62,7 +62,7 @@ buffer:
         name: SFT_data
         storage_type: file
         schema_type: sft
-        path: ${oc.env:TRINITY_SFT_DATASET_PATH,open-r1/Mixture-of-Thoughts}
+        path: ${oc.env:TRINITY_SFT_DATASET_PATH}
         split: 'train'
         format:
           prompt_type: messages

examples/mix_math/mix_math.yaml

@@ -61,7 +61,7 @@ buffer:
         name: math_sft
         storage_type: file
         schema_type: sft
-        path: ${oc.env:TRINITY_SFT_DATASET_PATH,open-r1/Mixture-of-Thoughts}
+        path: ${oc.env:TRINITY_SFT_DATASET_PATH}
         split: 'train'
         format:
           prompt_type: messages

examples/mix_vlm/README.md

@@ -0,0 +1,36 @@
+# MIX algorithm with VLM
+
+This is an example of using the [MIX](../../docs/sphinx_doc/source/tutorial/example_mix_algo.md) algorithm with Qwen2.5-VL-3B-Instruct model.
+
+> [!NOTE]
+> This feature is experimental and will be subject to change in future releases.
+
+The specific requirements are:
+
+```yaml
+vllm>=0.9.1,<0.10.0
+transformers<4.53.0
+qwen_vl_utils
+```
+
+## Prepare the SFT Dataset
+We use the [geometry3k](https://huggingface.co/datasets/hiyouga/geometry3k) dataset for training; we generate the [SFT dataset](https://huggingface.co/datasets/datajuicer/geometry_sft) by prompting Qwen2.5-VL-32B-Instruct model on the validation set. Note that this dataset only showcases the format of SFT data in this example, as shown below:
+```json
+{
+    "problem": "<image>Find $x$ so that $m || n$.",
+    "response": "To determine the value of $ x $ ... Answer:\n\\[\n\\boxed{63}\n\\]",
+    "images": [<image>]
+}
+```
+
+The config file is located in [`mix_vlm.yaml`](mix_vlm.yaml). To get better performance, feel free to try out different algorithm hyperparameters!
+
+## Run the Example
+
+Run the following command to start the training:
+```bash
+trinity run --config examples/mix_vlm/mix_vlm.yaml
+```
+
+The reward curve is shown below:
+![](../../docs/sphinx_doc/assets/mix_vlm_reward.png)

examples/mix_vlm/mix_vlm.yaml

@@ -0,0 +1,94 @@
+project: "Trinity-RFT"
+name: "mix_vlm"
+checkpoint_root_dir: ${oc.env:TRINITY_CHECKPOINT_ROOT_DIR,./checkpoints}
+algorithm:
+  algorithm_type: mix_chord
+  repeat_times: 8
+  optimizer:
+    lr: 1e-6
+  kl_loss_fn_args:
+    kl_coef: 0.0
+  entropy_loss_fn: mix
+  sample_strategy_args:
+    expert_data_ratio: 0.20
+  policy_loss_fn_args:
+    mu_warmup_steps: 200
+    mu_decay_steps: 400
+    mu_peak: 0.1
+    mu_valley: 0.1
+    enable_phi_function: false
+    clip_range: 0.2
+    sft_loss_agg_mode: "token-mean"
+    use_dynamic_bsz: true
+    ppo_mini_batch_size: 320 # 320 = 256 + 64
+    ppo_micro_batch_size_per_gpu: 4
+    ngpus_trainer: 4
+    train_batch_size_expert: 64
+    train_batch_size_usual: 256 # 32 batchsize * 8 repeat times
+model:
+  model_path: ${oc.env:TRINITY_MODEL_PATH,Qwen/Qwen2.5-1.5B-Instruct}
+  max_response_tokens: 10240
+  max_model_len: 11264
+cluster:
+  node_num: 1
+  gpu_per_node: 8
+buffer:
+  total_epochs: 4
+  batch_size: 32
+  train_batch_size: 320
+  explorer_input:
+    taskset:
+      name: geometry3k
+      storage_type: file
+      path: ${oc.env:TRINITY_TASKSET_PATH,hiyouga/geometry3k}
+      subset_name: 'default'
+      split: 'train'
+      format:
+        prompt_key: 'problem'
+        response_key: 'answer'
+        image_key: 'images'
+      rollout_args:
+        temperature: 1.0
+        logprobs: 0
+      workflow_args:
+        with_think: true
+    eval_tasksets: [] # you can add your own eval tasksets here
+    default_workflow_type: 'simple_mm_workflow'
+    default_reward_fn_type: 'math_boxed_reward'
+  trainer_input:
+    experience_buffer:
+      name: experience_buffer
+      storage_type: queue
+    auxiliary_buffers:
+      sft_dataset:
+        total_epochs: 25
+        name: geometry_sft
+        storage_type: file
+        schema_type: sft
+        path: datajuicer/geometry_sft
+        split: 'train'
+        format:
+          prompt_type: plaintext
+          prompt_key: 'problem'
+          response_key: 'response'
+          image_key: 'images'
+explorer:
+  eval_interval: 10
+  runner_per_model: 8
+  rollout_model:
+    engine_num: 4
+    tensor_parallel_size: 1
+    enable_prefix_caching: false
+    enforce_eager: true
+    dtype: bfloat16
+    seed: 42
+synchronizer:
+  sync_method: 'nccl'
+  sync_interval: 1
+  sync_timeout: 1200
+trainer:
+  save_interval: 50
+  grad_clip: 1.0
+  use_dynamic_bsz: true
+  max_token_len_per_gpu: 11264
+  ulysses_sequence_parallel_size: 2