Merge pull request #101 from martindevans/llama_sample_classifier_free_guidance

llama_sample_classifier_free_guidance

LLama/Native/NativeApi.Sampling.cs

@@ -30,6 +30,16 @@ namespace LLama.Native
         [DllImport(libraryName, CallingConvention = CallingConvention.Cdecl)]
         public static extern void llama_sample_frequency_and_presence_penalties(SafeLLamaContextHandle ctx, ref LLamaTokenDataArrayNative candidates, llama_token[] last_tokens, ulong last_tokens_size, float alpha_frequency, float alpha_presence);
 
+        /// <summary>
+        /// Apply classifier-free guidance to the logits as described in academic paper "Stay on topic with Classifier-Free Guidance" https://arxiv.org/abs/2306.17806
+        /// </summary>
+        /// <param name="ctx"></param>
+        /// <param name="candidates">A vector of `llama_token_data` containing the candidate tokens, the logits must be directly extracted from the original generation context without being sorted.</param>
+        /// <param name="guidance_ctx">A separate context from the same model. Other than a negative prompt at the beginning, it should have all generated and user input tokens copied from the main context.</param>
+        /// <param name="scale">Guidance strength. 1.0f means no guidance. Higher values mean stronger guidance.</param>
+        [DllImport(libraryName, CallingConvention = CallingConvention.Cdecl)]
+        public static extern void llama_sample_classifier_free_guidance(SafeLLamaContextHandle ctx, ref LLamaTokenDataArrayNative candidates, SafeLLamaContextHandle guidance_ctx, float scale);
+
         /// <summary>
         /// Sorts candidate tokens by their logits in descending order and calculate probabilities based on logits.
         /// </summary>