[BUG] MAP@50 is too low

[stevensagaert]

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Describe the problem

When evaluating a Utralytics yolo model on a dataset the reported map@50 is way lower than the one from ultralytics

Code to reproduce issue

here is a snippet of code for the eval (of course you still need to define your datasets & model & train it)

data.apply_model(model, label_field="predictions",confidence_thresh=conf)

results = data.evaluate_detections(
    "predictions",
    gt_field="detections",
    classes=['car'],
    eval_key="eval",
    iou=0.5, #threshold for map@50
    compute_mAP=True,
    use_boxes=False #use bounding boxes to calculate IoU
)

results.print_report()
map=results.mAP()
print("mAP@50:", map) 

# commands and/or screenshots here

System information

• OS Platform and Distribution (e.g., Linux Ubuntu 22.04): ubuntu 24.04
• Python version (python --version): 3.12.3
• FiftyOne version (fiftyone --version): 1.3.0
• FiftyOne installed from (pip or source): pip

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• Yes. I can contribute a fix for this bug independently
• Yes. I would be willing to contribute a fix for this bug with guidance
  from the FiftyOne community
• [ x] No. I cannot contribute a bug fix at this time