src/similarity.py

import numpy as np

from lmsim.metrics import Metrics, CAPA, EC

from src.dataloading import load_run_data_cached
from src.utils import softmax, one_hot

def load_data_and_compute_similarities(models: list[str], dataset: str, metric_name: str) -> np.array:
    # Load data
    probs = []
    gts = []
    for model in models:
        model_probs, model_gt = load_run_data_cached(model, dataset)
        probs.append(model_probs)
        gts.append(model_gt)
    
    # Compute pairwise similarities
    similarities = compute_pairwise_similarities(metric_name, probs, gts)
    return similarities


def compute_similarity(metric: Metrics, outputs_a: list[np.array], outputs_b: list[np.array], gt: list[int],) -> float:
    # Check that the models have the same number of responses
    assert len(outputs_a) == len(outputs_b) == len(gt), f"Models must have the same number of responses: {len(outputs_a)} != {len(outputs_b)} != {len(gt)}" 
    
    # Compute similarity values
    similarity = metric.compute_k(outputs_a, outputs_b, gt)
    
    return similarity


def compute_pairwise_similarities(metric_name: str, probs: list[list[np.array]], gts: list[list[int]]) -> np.array:
    # Select chosen metric
    if metric_name == "CAPA":
        metric = CAPA()
    elif metric_name == "CAPA (det.)":
        metric = CAPA(prob=False)
        # Convert logits to one-hot
        probs = [[one_hot(p) for p in model_probs] for model_probs in probs]
    elif metric_name == "Error Consistency":
        probs = [[one_hot(p) for p in model_probs] for model_probs in probs]
        metric = EC()
    else:
        raise ValueError(f"Invalid metric: {metric_name}") 

    similarities = np.zeros((len(probs), len(probs)))
    for i in range(len(probs)):
        for j in range(i, len(probs)):
            outputs_a = probs[i]
            outputs_b = probs[j]
            gt_a = gts[i].copy()
            gt_b = gts[j].copy()

            # Format softmax outputs
            if metric_name == "CAPA":
                outputs_a = [softmax(logits) for logits in outputs_a]
                outputs_b = [softmax(logits) for logits in outputs_b]

                # Remove indices where the ground truth differs
                # (This code assumes gt_a and gt_b are lists of integers.)
                indices_to_remove = [idx for idx, (a, b) in enumerate(zip(gt_a, gt_b)) if a != b]
                for idx in sorted(indices_to_remove, reverse=True):
                    del outputs_a[idx]
                    del outputs_b[idx]
                    del gt_a[idx]
                    del gt_b[idx]

            try:
                similarities[i, j] = compute_similarity(metric, outputs_a, outputs_b, gt_a)
            except Exception as e:
                print(f"Failed to compute similarity between models {i} and {j}: {e}")
                similarities[i, j] = np.nan
        
            similarities[j, i] = similarities[i, j]
    return similarities