Adding multiple optimizers to mlx lm (#1315)

* initial commmit

* adding more customized YAML configuartion

* update YAML example file

* Changed the switch to set opt_class

* removing muon

* using default arguments

* udpate

llms/mlx_lm/examples/lora_config.yaml

@@ -7,6 +7,15 @@ train: true
 # The fine-tuning method: "lora", "dora", or "full".
 fine_tune_type: lora
 
+# The Optimizer with its possible inputs
+optimizer: adamw
+# optimizer_config:
+#   adamw:
+#     betas: [0.9, 0.98]
+#     eps: 1e-6
+#     weight_decay: 0.05
+#     bias_correction: true
+
 # Directory with {train, valid, test}.jsonl files
 data: "/path/to/training/data"
 

llms/mlx_lm/lora.py

@@ -43,6 +43,11 @@ CONFIG_DEFAULTS = {
     "model": "mlx_model",
     "train": False,
     "fine_tune_type": "lora",
+    "optimizer": "adam",
+    "optimizer_config": {
+        "adam": {},
+        "adamw": {},
+    },
     "data": "data/",
     "seed": 0,
     "num_layers": 16,
@@ -95,14 +100,19 @@ def build_parser():
         choices=["lora", "dora", "full"],
         help="Type of fine-tuning to perform: lora, dora, or full.",
     )
-
+    parser.add_argument(
+        "--optimizer",
+        type=str,
+        choices=["adam", "adamw"],
+        default=None,
+        help="Optimizer to use for training: adam or adamw",
+    )
     parser.add_argument(
         "--mask-prompt",
         action="store_true",
         help="Mask the prompt in the loss when training",
         default=None,
     )
-
     parser.add_argument(
         "--num-layers",
         type=int,
@@ -229,11 +239,21 @@ def train_model(
     )
 
     model.train()
-    opt = optim.Adam(
-        learning_rate=(
-            build_schedule(args.lr_schedule) if args.lr_schedule else args.learning_rate
-        )
-    )
+
+    # Initialize the selected optimizer
+    lr = build_schedule(args.lr_schedule) if args.lr_schedule else args.learning_rate
+
+    optimizer_name = args.optimizer.lower()
+    optimizer_config = args.optimizer_config.get(optimizer_name, {})
+
+    if optimizer_name == "adam":
+        opt_class = optim.Adam
+    elif optimizer_name == "adamw":
+        opt_class = optim.AdamW
+    else:
+        raise ValueError(f"Unsupported optimizer: {optimizer_name}")
+
+    opt = opt_class(learning_rate=lr, **optimizer_config)
 
     # Train model
     train(